Patent Publication Number: US-7898363-B2

Title: Electric element and electric circuit

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 11/513,027 filed on Aug. 31, 2006. The priority applications Numbers JP2005-254620, JP2005-254690, JP2005-254750, JP2006-195565, upon which U.S. application Ser. No. 11/513,027 is based, are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to electric elements and electric circuits, and more particularly to an electric element and an electric circuit functioning as a noise filter with a wide frequency coverage and excellent high-frequency characteristics. 
     2. Description of Related Art 
     Recently, digital circuit technology such as LSI (Large Scale Integrated) circuit technology is adopted in not only computers and communication-related equipment but also consumer electronics and in-vehicle equipment. 
     The high-frequency current produced in the LSI circuit or the like does not stay in the vicinity of the LSI circuit but flows to the wide area of a component-mounted circuit board such as a printed-circuit board. The high-frequency current then inductively couples to signal wires and grounding wires and leaks as an electromagnetic wave from signal cables or the like. 
     In mixed-signal circuits in which analog circuitry and digital circuitry are combined, for example, a circuit in which a part of a conventional analog circuit is replaced with a digital circuit, and a digital circuit having analog input/output, one of the serious problems is electromagnetic interference from the digital circuit to the analog circuit. 
     The effective solution of this problem is to separate the LSI circuit, which is a source of the high-frequency current, from a power supplying system with respect to the high frequency, that is to say a “power decoupling” technique. Known as a noise filter employing the power decoupling technique is a transmission-line type noise filter (e.g. Japanese unexamined patent application No. 2004-80773). 
     This transmission-line type noise filter comprises a first electrical conductor, a second electrical conductor, a dielectric layer, a first anode and a second anode. Each first and second electrical conductor is in the form of a plate. The dielectric layer is disposed between the first and second electrical conductors. 
     The first anode is connected to one end of the first electrical conductor in a longitudinal direction, while the second anode is connected to the other end of the first electrical conductor in the longitudinal direction. The second electrical conductor functions as a cathode to connect to reference potential. The first electrical conductor, dielectric layer, and second electrical conductor constitute a capacitor. The thickness of the first electrical conductor is so set as to substantially prevent the temperature rise caused by a DC (direct current) component of the current flowing through the first electrical conductor. 
     The transmission-line type noise filter is connected between a DC power source and an LSI circuit so as to feed a DC current from the DC power source through a path made up of the first anode, the first electrical conductor and the second anode to the LSI circuit, while attenuating an AC (alternating current) current produced in the LSI circuit. 
     As discussed above, the transmission-line type noise filter has a structure of a capacitor, and uses the first and second electrical conductors, which are two electrodes of the capacitor, as transmission lines. 
     BRIEF SUMMARY OF THE INVENTION 
     However, the transmission-line type noise filter has an impedance expressed by (inductance/capacitance) 1/2 , and is not provided with a means for reducing inductance. The impedance shifts from a region where the capacitance is dominant to a region where the inductance is dominant with an increase in frequency. Accordingly, the conventional transmission-line type noise filters cannot have lower impedance than impedance determined by inherent inductance of the transmission-line type noise filters. 
     When the conventional transmission-line type noise filter, which is connected between a power source and an electrical load circuit such as a CPU (Central Processing Unit) operating at a predetermined frequency, is used as a decoupling circuit, it is difficult to fully confine an unwanted high-frequency current produced by the electrical load circuit within the vicinity of the electrical load circuit. In other words, there is a problem of leakage of the unwanted high-frequency current toward the other circuits. 
     Another problem is the difficulty in rapidly supplying an electric current from the power source to the electrical load circuit in response to rapid start-up of the electrical load circuit. 
     The present invention is made to solve the problems and has an object to provide an electric element capable of reducing impedance by decreasing the inductance. 
     The present invention has another object to provide an electric circuit capable of preventing leakage of an unwanted high-frequency current toward the power source. 
     The present invention has yet another object to provide an electric circuit enabling rapid start-up of the electrical load circuit as preventing the leakage of the unwanted high-frequency current toward the power source. 
     According to the present invention, the electric element is disposed between a power source and an electrical load circuit operating with an electric current from the power source, and comprises first conductive layers and second conductive layers. The first conductive layers are a conductor through which a first current flows from the power source side to the electrical load circuit side. The second conductive layers are a conductor through which a second current, which is a return current of the first current, flows from the electrical load circuit side to the power source side. The first conductor has a smaller inductance than its self-inductance when the first and second currents flow through the first and second conductors, respectively. 
     Preferably, the first conductor comprises n-number (n is a positive integer) of the first conductive layers each in the form of a flat plate, while the second conductor comprises m-number (m is a positive integer) of the second conductive layers each in the form of a flat plate and opposed to the first conductive layers. The n-number of first conductive layers and m-number of second conductive layers are alternately stacked. 
     Preferably, the electric element further comprises dielectrics. Each dielectric layer is disposed between a first conductive layer and a second conductive layer. Each of the n-number of first conductive layers passes the first current, which is an electric current from the power source, and is sandwiched between two second conductive layers connected to ground potential. 
     Preferably, the first current flows in the opposite direction to the second current. 
     Preferably, where the length of the first and second conductive layer in the direction perpendicular to the direction in which the first and second currents flow is W, and the length of the first and second conductive layers along the direction in which the first and second currents flow is L, an overlap part between the first conductive layer and second conductive layer holds W≧L. 
     Preferably, the electric element further comprises first to fourth electrodes. The first electrode is electrically connected to one end of the n-number of first conductive layers in a first direction in which the first current flows in the first conductive layers. The second electrode is electrically connected to the other end of the n-number of first conductive layers in the first direction. The third electrode is electrically connected to one end of the m-number of second conductive layers in a second direction in which the second current flows in the second conductive layers. The fourth electrode is electrically connected to the other end of the m-number of second conductive layers in the second direction. 
     According to the present invention, the electric element is in the form of an approximately rectangular parallelepiped and comprises a plurality of first conductive layers, a plurality of second conductive layers, a plurality of dielectrics, and first to fourth electrodes. The plurality of first conductive layers are disposed approximately parallel to the bottom face of the rectangular parallelepiped. The plurality of second conductive layers are disposed approximately parallel to the bottom face of the rectangular parallelepiped. Each of the plurality of dielectrics is disposed between a first conductive layer and a second conductive layer. The first electrode is connected to one end of the plurality of first conductive layers. The second electrode is connected to the other end of the plurality of first conductive layers. The third electrode is connected to the plurality of second conductive layers in the proximity of one end of the second conductive layers. The fourth electrode is connected to the plurality of second conductive layers in the proximity of the other end of second conductive layers. 
     Preferably, the first conductive layers are longer than the second conductive layers in a first direction from a first side face disposed approximately vertically on the bottom face of the rectangular parallelepiped to a second side face opposed to the first side face, while the second conductive layers are longer than the first conductive layers in a second direction from a third side face disposed approximately vertically on the bottom face of the rectangular parallelepiped and approximately perpendicular to the first and second side faces to a fourth side face opposed to the third side face. 
     Preferably, the first conductive layers are longer than the second conductive layers in a first direction from a first side face disposed approximately vertically on the bottom face of the rectangular parallelepiped to a second side face opposed to the first side face, while having approximately the same dimension as the second conductive layers in a second direction from a third side face disposed approximately vertically on the bottom face of the rectangular parallelepiped and approximately perpendicular to the first and second side faces to a fourth side face opposed to the third side face. The second conductive layers have extending portions each connected to the third and fourth electrodes. 
     Preferably, the first electrode is connected to the plurality of first conductive layers on the first side face, while the second electrode is connected to the plurality of first conductive layers on the second side face. The third electrode is connected to the plurality of second conductive layers at positions closer to the first side face than the midpoint between the first side face and the second side face, on the third and fourth side faces, while the fourth electrode is connected to the plurality of second conductive layers at a position closer to the second side face than the midpoint, on the third and fourth side faces. 
     Preferably, the first conductive layers has approximately the same dimension as the second conductive layers in a first direction from a first side face disposed approximately vertically on the bottom face of the rectangular parallelepiped to the second side face opposed to the first side face, and in a second direction from a third side face disposed approximately vertically on the bottom face of the rectangular parallelepiped and approximately perpendicular to the first and second side faces to a fourth side face opposed to the third side face. The first conductive layers have first and second extending portions extending toward the first and the second side faces, respectively, while the second conductive layers have third and fourth extending portions extending toward the first and the second side faces, respectively. 
     Preferably, the first electrode is connected to the first extending portions of the plurality of first conductive layers on the first side face, while the second electrode is connected to the second extending portions of the plurality of first conductive layers on the second side face. The third electrode is connected to the third extending portions of the plurality of second conductive layers on the first side face, while the fourth electrode is connected to the fourth extending portions of the plurality of second conductive layers on the second side face. 
     Preferably, the first extending portions are formed closer to the third side face than the midpoint between the third side face and the fourth side face in the second direction, while the second extending portions are formed closer to the fourth side face than the midpoint in the second direction. The third extending portions are formed closer to the fourth side face than the midpoint in the second direction, while the fourth extending portions are formed closer to the third side face than the midpoint in the second direction. 
     Preferably, the first conductive layer has approximately the same dimension as the second conductive layer in a first direction from a first side face disposed approximately vertically on the bottom face of the rectangular parallelepiped to the second side face opposed to the first side face, and in a second direction from a third side face disposed approximately vertically on the bottom face of the rectangular parallelepiped and approximately perpendicular to the first side face and the second side face to a fourth side face opposed to the third side face. The first conductive layers have first and second extending portions extending toward the third side face, while the second conductive layers have third and fourth extending portions extending toward the fourth side face. 
     Preferably, the first electrode is connected to the first extending portions of the plurality of first conductive layers on the third side face, while the second electrode is connected to the second extending portions of the plurality of first conductive layers on the third side face. The third electrode is connected to the third extending portions of the plurality of second conductive layers on the fourth side face, while the fourth electrode is connected to the fourth extending portions of the plurality of second conductive layers on the fourth side face. 
     Preferably, where the length of the first and second conductive layers in the first direction is W and the length of first and second conductive layers in the second direction is L, an overlap part between the first conductive layer and second conductive layer holds W≧L. 
     Preferably, where the length of first and second conductive layers in the first direction is W and the length of first and second conductive layers in the second direction is L, an overlap part between the first conductive layer and second conductive layer holds L&gt;W. 
     Preferably, the first and second conductive layers are composed of metallic materials containing nickel as a main material. The dielectrics are composed of ceramic materials containing BaTiO 3  as a main material. 
     An electric circuit according to the present invention includes any one of electric elements disclosed in the present invention disposed between a power source and an electrical load. The plurality of first conductive layers constitute a path through which the first current flows from the power source side to the load side, while the plurality of second conductive layers constitute a path through which the second current as a return current of the first current flows. 
     The electric circuit according to the present invention further includes an electric element connected to the power source and a capacitor connected between the electric element and the electrical load. The electric element is any one of electric elements disclosed in the present invention. 
     Preferably, the first electrode of the electric element is connected to a positive electrode of the power source. The second electrode of the electric element is connected to an anode of the capacitor. The third electrode of the electric element is connected to a cathode of the capacitor. The fourth electrode of the electric element is connected to a negative electrode of the power source. The anode of the capacitor is connected to a positive electrode of the electrical load. The cathode of the capacitor is connected to a negative electrode of the electric element. 
     The electric circuit according to the present invention includes a first electric element having an approximately rectangular plane and connected to the power source, and a second electric element having the approximately rectangular plane and connected to the electrical load. A first dimension of the first electric element in a lateral direction of the rectangle is longer than a second dimension of the first electric element in a vertical direction of the rectangle, while the third dimension of the second electric element in the lateral direction of the rectangle is shorter than a fourth dimension of the second electric element in the vertical direction of the rectangle. 
     In the present invention, when the first and second currents flow in the first and second conductors, respectively, the inductance of the first conductor becomes smaller than its self-inductance by mutual inductance between the first conductor and the second conductor. Thus, impedance of the electric element is reduced with the decrease in inductance of the first conductor. 
     The present invention can thus reduce impedance through the reduction of the inductance. 
     According to the present invention, the electric element comprises a plurality of first conductive layers, a plurality of second conductive layers, a plurality of dielectrics, first to fourth electrodes. Each of the plurality of dielectrics is disposed between a first conductive layer and a second conductive layer. The first and second electrodes are connected to the plurality of first conductive layers at opposite ends thereof, while the third and fourth electrodes are connected to the plurality of second conductive layers at the opposite ends thereof. This configuration allows an electric current to flow through the first electrode, plurality of first conductive layers and second electrode in this order and allows a return current of the electric current to flow through the fourth electrode, plurality of second conductive layers and third electrode in this order. Because the first conductive layers and second conductive layers have the electric current flowed in the opposite direction to each other, the inductance of the first conductive layer becomes smaller than its self-inductance by mutual inductance between the first and second conductive layers. 
     The present invention can thus reduce impedance through the reduction of inductance. 
     According to the present invention, the electric circuit comprises an electric element disposed between a power source and an electrical load. The electric element confines an unwanted high-frequency current produced by the electrical load within circuitry built up with the electrical load and electric element. 
     The present invention can thus prevent the unwanted high-frequency current from leaking toward the power source. 
     According to the present invention, an electric circuit comprises an electric element connected to a power source and a capacitor connected between the electric element and an electrical load. The electric circuit stores power source currents supplied from the power source to supply the stored power source current to the electrical load, while confining the unwanted high-frequency current produced by the electrical load within circuitry built up with the electrical load and electric element. 
     Thus, the present invention can prevent the unwanted high-frequency current from leaking toward the power source and enable to rapidly supply the power source current to the electrical load circuit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating the structure of an electric element according to the first embodiment of the present invention. 
         FIG. 2  a diagram for describing dimensions of dielectric layers and conductive plates shown in  FIG. 1 . 
         FIG. 3  is a plan view illustrating two adjacent conductive plates. 
         FIGS. 4A and 4B  are cross-sectional views of the electric element shown in  FIG. 1 . 
         FIGS. 5A to 5C  are the first process drawings for describing a fabricating method of the electric element shown in  FIG. 1   
         FIGS. 6A and 6B  are the second process drawings for describing a fabricating method of the electric element shown in  FIG. 1   
         FIG. 7  is a perspective view for describing the functions of the electric element shown in  FIG. 1 . 
         FIG. 8  is a view for describing magnetic flux density produced by an electric current passing through a conductive wire. 
         FIG. 9  is a view for describing effective inductance upon the occurrence of magnetic interference between two conductive wires. 
         FIG. 10  is a schematic view illustrating the structure of another electric element according to the first embodiment of the present invention. 
         FIG. 11  is a conceptual illustration showing the electric element shown in  FIG. 1  in an operating state. 
         FIG. 12  illustrates the frequency-dependent attenuation characteristics in the electric element shown in  FIG. 1 . 
         FIG. 13  is a view illustrating the frequency dependence of impedance in the electric element shown in  FIG. 1 . 
         FIG. 14  is another view illustrating the frequency dependence of impedance in the electric element shown in  FIG. 1 . 
         FIG. 15  is yet another view illustrating the frequency dependence of impedance in the electric element shown in  FIG. 1 . 
         FIG. 16  is yet another view illustrating the frequency dependence of impedance in the electric element shown in  FIG. 1 . 
         FIG. 17  is a schematic view illustrating the structure of an electric element according to the second embodiment. 
         FIGS. 18A to 18E  are plan views of dielectric layers and conductive plates shown in  FIG. 17  and a bottom view of the electric element shown in  FIG. 17 . 
         FIG. 19  is a schematic view illustrating the structure of an electric element according to the third embodiment. 
         FIGS. 20A to 20E  are plan views of the dielectric layers and conductive plates shown in  FIG. 19  and a bottom view of the electric element shown in  FIG. 19 . 
         FIG. 21  is a schematic view illustrating the structure of an electric element according to the fourth embodiment. 
         FIGS. 22A to 22E  are plan views of the dielectric layers and conductive plates shown in  FIG. 21  and a bottom view of the electric element shown in  FIG. 21 . 
         FIG. 23  is a schematic view illustrating the first modification of the electric element according to the embodiments of the present invention. 
         FIG. 24  is a plan view of the electric element shown in  FIG. 23 . 
         FIG. 25  is a schematic view illustrating the second modification of the electric element according to the embodiments of the present invention. 
         FIGS. 26A and 26B  are side views of the electric element shown in  FIG. 25 . 
         FIG. 27  is a schematic view illustrating the third modification of the electric element according to the embodiments of the present invention. 
         FIGS. 28A and 28B  are a plan view and a side view, respectively, illustrating the electric element shown in  FIG. 27 . 
         FIG. 29  is a schematic view illustrating the fourth modification of the electric element according to the embodiments of the present invention. 
         FIG. 30  is a plan view of the electric element viewed from direction C in  FIG. 29 . 
         FIG. 31  is a schematic view illustrating the structure of an electric circuit according to the fifth embodiment. 
         FIG. 32  is a schematic view illustrating the structure of an electric circuit according to the sixth embodiment. 
         FIG. 33  is a conceptual illustration showing the electric element shown in  FIG. 32  in an operating state. 
         FIG. 34  is a perspective view illustrating the structure of the capacitor shown in  FIG. 32 . 
         FIG. 35  is an another schematic view illustrating the structure of an electric circuit according to the sixth embodiment. 
         FIG. 36  is a cross-sectional view illustrating the electric element and capacitor shown in  FIG. 35 . 
         FIG. 37  is a perspective view illustrating an exemplary electric circuit according to the sixth embodiment. 
         FIG. 38  is a plan view of the electric circuit viewed from direction A in  FIG. 37 . 
         FIG. 39  is a plan view of the electric circuit viewed from direction B in  FIG. 37 . 
         FIG. 40  is a plan view of the electric circuit viewed from direction C in  FIG. 37 . 
         FIG. 41  is a cross-sectional view of the electric circuit taken along line XXXXI-XXXXI in  FIG. 37 . 
         FIG. 42  is a schematic view illustrating the structure of the electric circuit according to the seventh embodiment. 
         FIG. 43  is a bottom view illustrating the electric element shown in  FIG. 42 . 
         FIG. 44  is a plan view illustrating a board on which the electric circuit shown in  FIG. 42  is mounted. 
         FIG. 45  is a schematic view illustrating the structure of the other electric circuits according to the seventh embodiment. 
         FIG. 46  is a plan view of the two electric elements shown in  FIG. 45 . 
         FIG. 47  is a side view of the electric circuit shown in  FIG. 45  viewed from direction A. 
         FIG. 48  is a bottom view of the electric circuit shown in  FIG. 45 . 
     
    
    
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when reviewed in conjunction with the accompanying drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings, a detailed description will be made on embodiments of the present invention. Components identical or equivalent to each other in the drawings are denoted by the same reference number, and will not be further explained to avoid repetition. 
     The First Embodiment 
       FIG. 1  is a schematic view illustrating the structure of an electric element according to the first embodiment of the present invention. Referring to  FIG. 1 , the electric element  100  of the first embodiment of the present invention is in the form of an approximately rectangular parallelepiped and comprises dielectric layers  1  to  5 , conductive plates  11 ,  12 ,  21  to  23 , side anode electrodes  10 A,  10 B, anode electrodes  10 C,  10 D, side cathode electrodes  20 A,  20 B,  20 C,  20 D, and cathode electrodes  20 E,  20 F. 
     The dielectric layers  1  to  5  are stacked in sequence. The conductive plates  11 ,  12 ,  21  to  23  are in the form of a flat plate each. The conductive plate  21  is placed between the dielectric layers  1  and  2 , while the conductive plate  11  is placed between the dielectric layers  2  and  3 . The conductive plate  22  is placed between the dielectric layers  3  and  4 , while the conductive plate  12  is placed between the dielectric layers  4  and  5 . The conductive plate  23  is placed on a principal surface  5 A of the dielectric layer  5 . The dielectric layers  1  to  5  support the conductive plates  21 ,  11 ,  22 ,  12 , and  23 , respectively. The conductive plates  11 ,  12 ,  21  to  23  are arranged approximately parallel to the bottom face ( 100 C) of the rectangular parallelepiped. 
     The side anode electrode  10 A is connected to one end of the conductive plates  11 ,  12 , and formed on a side face  100 A (which is made up of the side faces of the dielectric layers  1  to  4 ) of the electric element  100 . The side anode electrode  10 B is connected to the other end of the conductive plates  11 ,  12 , and formed on a side face  100 B (which is made up of the side faces of the dielectric layers  1  to  4 ) opposed to the side face  100 A of the electric element  100 . The side anode electrode  10 B is opposed to the side anode electrode  10 A. 
     The anode electrode  10 C is disposed on the bottom face  100 C of the electric element  100  and connected to the side anode electrode  10 A. The anode electrode  10 D is disposed on the bottom face  100 C of the electric element  100  and connected to the side anode electrode  10 B. 
     The side cathode electrode  20 A is connected to the conductive plates  21  to  23  in the proximity of one end of the conductive plates  21  to  23  and disposed on the front face  100 D of the electric element  100 . The side cathode electrode  20 B is connected to the conductive plates  21  to  23  in the proximity of one end of the conductive plates  21  to  23  and disposed on the rear face  100 E opposite to the front face  100 D of the electric element  100 . The side cathode electrode  20 B is opposed to the side cathode electrode  20 A. 
     The side cathode electrode  20 C is connected to the conductive plates  21  to  23  in the proximity of the other end of the conductive plates  21  to  23  and disposed on the front face  100 D of the electric element  100 . The side cathode electrode  20 D is connected to the conductive plates  21  to  23  in the proximity of the other end of the conductive plates  21  to  23  and disposed on the rear face  100 E opposite to the front face  100 D of the electric element  100 . The side cathode electrode  20 D is opposed to the side cathode electrode  20 C. 
     The cathode electrode  20 E is connected to the side cathode electrodes  20 A and  20 B and arranged on the bottom face  100 C of the electric element  100 . The cathode electrode  20 F is connected to the side cathode electrodes  20 C and  20 D and arranged on the bottom face  100 C of the electric element  100 . 
     As described above, the electric element  100  has the conductive plates  11 ,  12 ,  21  to  23  alternately disposed with the dielectric layers  1  to  5  interposed therebetween, and includes the two anode electrodes  10 C,  10 D and two cathode electrodes  20 E,  20 F. 
     The dielectric layers  1  to  5  are composed of, for example, barium titanate (BaTiO 3 ). The side anode electrodes  10 A,  10 B, anode electrodes  10 C,  10 D, conductive plates  11 ,  12 ,  21  to  23 , side cathode electrodes  20 A,  20 B,  20 C,  20 D and cathode electrodes  20 E,  20 F are composed of, for example, nickel (Ni). 
       FIG. 2  is a diagram for describing the dimensions of the dielectric layers  1 ,  2  and conductive plates  11 ,  21  shown in  FIG. 1 . Referring to  FIG. 2 , each of the dielectric layers  1 ,  2  has a length of L 1  along the direction DR 1 , which is the direction of a current flowing in the conductive plates  11 ,  21 , a width of W 1  along the direction DR 2  perpendicular to the direction DR 1 , and a thickness of D 1 . The length L 1 , width W 1 , and thickness D 1  are set, for example, at 15 mm, 13 mm, and 25 μm, respectively. 
     The conductive plate  11  has length L 1  and width W 2 . Width W 2  is set, for example, at 11 mm. The conductive plate  21  has length L 2  and width W 1 . Length L 2  is set, for example, at 13 mm. Each of the conductive plates  11 ,  21  has a thickness, for example, in a range between 10 μm to 20 μm. 
     Each of the dielectric layers  3  to  5  has the same length L 1 , width W 1 , and thickness D 1  as those of the dielectric layers  1 ,  2  shown in  FIG. 2 . The conductive plate  12  has the same length L 1 , width W 2  and thickness as those of the conductive plate  11  shown in  FIG. 2 . Each of the conductive plates  22 ,  23  has the same length L 2 , width W 1 , and thickness as those of the conductive plate  21  shown in  FIG. 2 . 
     As discussed above, the dielectric layers  1  to  5  and conductive plates  11 ,  12 ,  21  to  23  have approximately rectangular planes. The conductive plates  11 ,  12  are different in length and width from the conductive plates  21  to  23 . These differences are made to prevent shorting between the side anode electrodes  10 A,  10 B connected to the conductive plates  11 ,  12  and the side cathode electrodes  20 A,  20 B,  20 C,  20 D connected to the conductive plates  21  to  23 . 
       FIG. 3  is a plan view illustrating two adjacent conductive plates. Suppose the conductive plate  11  and conductive plate  21  are in one plane, with reference to  FIG. 3 , the conductive plates  11  and  21  have an overlap part  20 . The overlap part  20  between the conductive plate  11  and conductive plate  21  has length L 2  and width W 2 . Overlap parts between the conductive plate  11  and conductive plate  22 , between the conductive plate  12  and conductive plate  22 , and between the conductive plate  12  and conductive plate  23  have the same length L 2  and width W 2  as those of the overlap part  20 . In the present invention, when the electric element  100  functions mainly as a noise filter, length L 2  and width W 2  are set so as to hold L 2 &gt;W 2 . When the electric element  100  functions mainly as a capacitor, length L 2  and width W 2  are set so as to establish W 2 ≧L 2 . 
       FIGS. 4A and 4B  are cross-sectional views of the electric element  100  shown in  FIG. 1 .  FIG. 4A  is a cross-sectional view of the electric element  100  as taken along line IVA-IVA of  FIG. 1 , while  FIG. 4B  is a cross-sectional view of the electric element  100  as taken along line IVB-IVB of  FIG. 1 . 
     Referring to  FIG. 4A , the conductive plate  21  is in contact with both dielectric layers  1  and  2 , while the conductive plate  11  is in contact with both dielectric layers  2  and  3 . The conductive plate  22  is in contact with both dielectric layers  3  and  4 , while the conductive plate  12  is in contact with both dielectric layers  4  and  5 . In addition, the conductive plate  23  is in contact with the dielectric layer  5 . 
     The side cathode electrodes  20 C,  20 D are not connected to the conductive plates  11 ,  12 , but to the conductive plates  21  to  23 . The cathode electrode  20 F is disposed under the underside  1 A of the dielectric layer  1  and connected to the side cathode electrodes  20 C,  20 D. 
     Referring to  FIG. 4B , the side anode electrodes  10 A,  10 B are not connected to the conductive plates  21  to  23 , but to the conductive plates  11 ,  12 . The anode electrodes  10 C,  10 D are disposed under the underside  1 A of the dielectric layer  1  and connected to the side anode electrodes  10 A,  10 B, respectively. 
     As a result, a group of conductive plate  21 , dielectric layer  2  and conductive plate  11 , a group of the conductive plate  11 , dielectric layer  3  and conductive plate  22 , a group of the conductive plate  22 , dielectric layer  4  and conductive plate  12 , and a group of the conductive plate  12 , dielectric layer  5  and conductive plate  23  constitute four capacitors connected in parallel between the anode electrodes  10 C and  10 D and between the cathode electrodes  20 E and  20 F. 
     Each capacitor has an electrode area equal to the overlap part  20  (see  FIG. 3 ) of the two adjacent conductive plates. 
     As discussed above, the electric element  100  comprises the conductive plates  11 ,  12  disposed parallel to the bottom face  100 C of the approximately rectangular parallelepiped, the conductive plates  21  to  23  disposed parallel to the bottom face  100 C of the approximately rectangular parallelepiped, the dielectric layers  1  to  5  each disposed between either of the conductive plate  11  or  12  and any of the conductive plates  21  to  23 , the side anode electrode  10 A and anode electrode  10 C connected to one end of the conductive plates  11 ,  12 , the side anode electrode  10 B and anode electrode  10 D connected to the other end of the conductive plates  11 ,  12 , the side cathode electrodes  20 A,  20 B and cathode electrode  20 E connected to the conductive plates  21  to  23  in the proximity of one end of the conductive plates  21  to  23 , and the side cathode electrodes  20 C,  20 D and cathode electrode  20 F connected to the conductive plates  21  to  23  in the proximity of the other end of the conductive plates  21  to  23 . The side anode electrode  10 A is connected to the conductive plates  11 ,  12  on the side face  100 A, while the side anode electrode  10 B is connected to the conductive plates  11 ,  12  on the side face  100 B opposed to the side face  100 A. The side cathode electrode  20 A is connected to the conductive plates  21  to  23  on the front face  100 D arranged approximately perpendicular to the side faces  100 A,  100 B and approximately vertically to the bottom face  100 C, while the side cathode electrode  20 B is connected to the conductive plates  21  to  23  on the rear face  100 E opposed to the front face  100 D which is arranged approximately perpendicular to the side faces  100 A,  100 B and approximately vertically on the bottom face  100 C. The side cathode electrode  20 C is connected to the conductive plates  21  to  23  on the front face  100 D approximately perpendicular to the side faces  100 A,  100 B and approximately vertically on the bottom face  100 C, while the side cathode electrode  20 D is connected to the conductive plates  21  to  23  on the rear face  100 E opposed to the front face  100 D which is arranged approximately perpendicular to the side faces  100 A,  100 B and approximately vertically on the bottom face  100 C. 
     In the electric element  100 , the side anode electrode  10 A and anode electrode  10 C constitute “a first electrode”. The side anode electrode  10 B and anode electrode  10 D constitute “a second electrode”. The side cathode electrodes  20 A,  20 B and cathode electrode  20 E constitute “a third electrode”. The side cathode electrodes  20 C,  20 D and cathode electrode  20 F constitute “a fourth electrode”. 
       FIGS. 5A to 5C  and  FIGS. 6A and 6B  are the first and second process drawings, respectively, for describing a fabricating method of the electric element  100  shown in  FIG. 1 . Referring to  FIGS. 5A to 5C , a green sheet, which will be the dielectric layer  1  (BaTiO 3 ), having a length of L 1 , width of W 1  and thickness of D 1  is prepared. In an area having length L 2  and width W 1  on the front face  1 B of the green sheet, Ni paste is applied by screen printing to form a Ni conductive plate  21 . 
     Similarly, after the dielectric layers  3 ,  5  composed of BaTiO 3  are prepared, the conductive plates  22 ,  23  composed of Ni are formed on the prepared dielectric layers  3 ,  5 , respectively (see  FIG. 5A ). 
     Subsequently, a green sheet, which will be the dielectric layer  2  (BaTiO 3 ), having length L 1 , width W 1  and thickness D 1  are prepared. In an area having length L 1  and width W 2  on the front face  2 A of the green sheet, Ni paste is applied by screen printing to form a Ni conductive plate  11 . 
     Similarly, after the dielectric layer  4  composed of BaTiO 3  is prepared, the conductive plate  12  composed of Ni is formed on the prepared dielectric layer  4  (see  FIG. 5B ). 
     The green sheets of the dielectric layers  1  to  5  on which conductive plates  21 ,  11 ,  22 ,  12 , and  23  are formed respectively, are successively laminated (see  FIG. 5C ). This successive lamination results in alternate lamination of the conductive plates  11 ,  12  to be connected to the anode electrodes  10 C,  10 D and the conductive plates  21  to  23  to be connected to the cathode electrodes  20 E,  20 F. 
     Then, the Ni paste is applied by the screen printing to form the side anode electrodes  10 A,  10 B, anode electrodes  10 C,  10 D, side cathode electrodes  20 A,  20 B,  20 C,  20 D and cathode electrodes  20 E,  20 F (see  FIGS. 6A and 6B ). The element fabricated as shown in  FIG. 6B  is fired at a temperature of 1350 degrees C. to complete the electric element  100 . Alternatively, the side electrodes (external electrodes) can be made of materials having a lower melting point and higher conductivity than that of the internal electrodes (conductive plates  11 ,  12 ,  21  to  23 ) by use of post-fire. Further, the fired side electrodes (external electrodes) may require plating with Ni, Au, Su or other materials, if necessary, under consideration of solder wettability. 
     There is another method of fabricating the electric element  100  without the green sheets. In the method, a process of printing and drying dielectric paste and a process of printing a conductor on the dried dielectric paste are repeatedly performed to stack the dielectric layers and conductive plates. 
       FIG. 7  is a perspective view for describing the functions of the electric element  100  shown in  FIG. 1 . Referring to  FIG. 7 , with the cathode electrodes  20 E,  20 F connected to ground potential, the electric element  100  passes the DC current so that the DC current flows in the conductive plates  11 ,  12  in the opposite direction to the DC current flowing in the conductive plates  21  to  23 . 
     If a DC current is fed to the electric element  100  so as to flow from the anode electrode  10 C to the anode electrode  10 D, for example, the DC current flows from the anode electrode  10 C through the side anode electrode  10 A to the conductive plates  11 ,  12 , passes through the conductive plates  11 ,  12  in the direction of arrow  30 , and further passes through the side anode electrode  10 B to the anode electrode  10 D. 
     A return current of the current having flowed in the conductive plates  11 ,  12  passes from the cathode electrode  20 F through the side cathode electrodes  20 C,  20 D to the conductive plates  21  to  23 . The return current then passes through the conductive plates  21  to  23  in the direction of arrow  40 , which is opposite to the arrow  30 , and further flows in the side cathode electrodes  20 A,  20 B to the cathode electrode  20 E. 
     In this configuration, the DC current I 1  flowing through the conductive plates  11 ,  12  and the DC current I 2  flowing through the conductive plates  21  to  23  are equal in magnitude and opposite in direction. 
       FIG. 8  is a view for describing magnetic flux density produced by an electric current passing through a conductive wire.  FIG. 9  is a view for describing effective inductance upon the occurrence of magnetic interference between two conductive wires. 
     Referring to  FIG. 8 , when an electric current I is flowing in an infinitely long straight wire, a magnetic flux density B at a point P at distance a from the wire is expressed by: 
     
       
         
           
             
               
                 
                   B 
                   = 
                   
                     
                       
                         μ 
                         0 
                       
                       ⁢ 
                       I 
                     
                     
                       2 
                       ⁢ 
                       π 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       r 
                     
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
           
         
       
     
     In this expression, μ 0  indicates magnetic permeability in a vacuum. 
     Alternatively, when the conductive wire shown in  FIG. 8  is replaced with two conductive wires that mutually cause magnetic interference, mutual inductance L 12  is expressed as below, where self-inductances of the two wires are L 11  and L 22 , respectively, and coupling coefficient is k(0&lt;k&lt;1), and the mutual inductance of the two conductive wires is L 12 .
 
 L   12   =k ·√{square root over ( L   11   ·L   22 )}  (2)
 
     If L 11 =L 22 , the mutual inductance L 12  is expressed by:
 
 L   12   =k·L   11   (3)
 
     Referring to  FIG. 9 , given that a conductive wire A and conductive wire B are connected by a lead wire C and both have an electric current flowing therethrough that are equal in magnitude but opposite in direction, effective inductance L 11effective  of the conductive wire A is expressed by:
 
 L   11effective   =L   11   −L   12   (4)
 
     As discussed above, the magnetic interference occurred between the conductive wire A and conductive wire B creates the mutual inductance L 12 , which causes the effective inductance L 11effective  of the conductive wire A to be smaller than the self-inductance L 11  of the conductive wire A. This is because the direction of magnetic flux φ A  produced by the electric current I flowing in the conductive wire A is opposite to the direction of magnetic flux φ B  produced by the electric current −I flowing in the conductive wire B, therefore effective magnetic flux density produced by the electric current I in the conductive wire A is reduced. 
     In the above-discussed electric element  100 , the conductive plate  11  is located 25 μm away from the conductive plates  21 ,  22  and the conductive plate  12  is located 25 μm away from the conductive plates  22 ,  23 . Because of this, magnetic interference occurs between the conductive plate  11  and each conductive plate  21  and  22  and between the conductive plate  12  and each conductive plate  22  and  23 . Since the DC current I 1  flowing in the conductive plates  11 ,  12  and the DC current I 2  flowing in the conductive plates  21  to  23  are equal in magnitude but opposite in direction, the effective inductance of the conductive plates  11 ,  12  becomes smaller than the self-inductance of the conductive plates  11 ,  12  due to the mutual inductance between the conductive plates  11 ,  12  and the conductive plates  21  to  23 . 
     As a result, the effective inductance L of the entire electric element  100  is reduced. 
     The above-discussed electric element  100  with four capacitors connected in parallel results in having more effective capacitance C as compared with an electric element with one capacitor. 
     In conclusion, the electric element  100  can reduce its impedance with an increase in the effective capacitance C in a low-frequency range dominated by capacitance, while the electric element  100  can reduce its impedance with a decrease in the effective inductance L in a high-frequency range dominated by inductance. 
     As a result, the electric element  100  has relatively low impedance for broadband frequencies. 
       FIG. 10  is a schematic view illustrating the structure of another electric element according to the first embodiment. The electric element of the first embodiment may be replaced with an electric element  101  shown in  FIG. 10 . Referring to  FIG. 10 , the conductive plate  23  provided in the electric element  100  shown in  FIG. 1  is removed from the electric element  101 . The electric element  101  includes an anode electrode  120  instead of the side anode electrode  10 A and anode electrode  10 C, an anode electrode  130  instead of the side anode electrode  10 B and anode electrode  10 D and all other components included in the electric element  100 . 
     The anode electrode  120  is composed of nickel (Ni) and arranged on the side face  100 A, and a part of the bottom face  100 C, front face  100 D, rear face  100 E and top face  100 F of the electric element  101 . More specifically, the anode electrode  120  includes a side anode electrode  121  and strip electrodes  122  to  125 . The side anode electrode  121  is disposed all over the side face  100 A of the electric element  101 . The strip electrode  122  is disposed on the bottom face  100 C of the electric element  101  and in the proximity of one end of the conductive plates  11 ,  12 ,  21 ,  22 . The strip electrode  123  is disposed on the front face  100 D of the electric element  101  and in the proximity of one end of the conductive plates  11 ,  12 ,  21 ,  22 . The strip electrode  124  is disposed on the top face  100 F of the electric element  101  and in the proximity of one end of the conductive plates  11 ,  12 ,  21 ,  22 . The strip electrode  125  is disposed on the rear face  100 E of the electric element  101  and in the proximity of one end of the conductive plates  11 ,  12 ,  21 ,  22 . The side anode electrode  121  is connected to one end of the conductive plates  11 ,  12 . 
     The anode electrode  130  is composed of nickel (Ni) and arranged on the side face  100 B, and a part of the bottom face  100 C, front face  100 D, rear face  100 E and top face  100 F of the electric element  101 . More specifically, the anode electrode  130  includes a side anode electrode  131  and strip electrodes  132  to  135 . The side anode electrode  131  is disposed all over the side face  100 B of the electric element  101 . The strip electrode  132  is disposed on the bottom face  100 C of the electric element  101  and in the proximity of the other end of the conductive plates  11 ,  12 ,  21 ,  22 . The strip electrode  133  is disposed on the front face  100 D of the electric element  101  and in the proximity of the other end of the conductive plates  11 ,  12 ,  21 ,  22 . The strip electrode  134  is disposed on the top face  100 F of the electric element  101  and in the proximity of the other end of the conductive plates  11 ,  12 ,  21 ,  22 . The strip electrode  135  is disposed on the rear face  100 E of the electric element  101  and in the proximity of the other end of the conductive plates  11 ,  12 ,  21 ,  22 . The side anode electrode  131  is connected to the other end of the conductive plates  11 ,  12 . 
       FIG. 11  is a conceptual illustration showing the electric element  100  shown in  FIG. 1  in an operating state. Referring to  FIG. 11 , the electric element  100  is connected between a power source  90  and a CPU (Central Processing Unit)  110 . The electric element  100  has cathode electrodes  20 E,  20 F connected to ground potential. The power source  90  has a positive terminal  91  and negative terminal  92 . The CPU  110  has a positive terminal  111  and negative terminal  112 . 
     A lead wire  121  has one end connected with the positive terminal  91  of the power source  90  and the other end connected with the anode electrode  10 C of the electric element  100 . A lead wire  122  has one end connected with the negative terminal  92  of the power source  90  and the other end connected with the cathode electrode  20 E of the electric element  100 . 
     A lead wire  123  has one end connected with the anode electrode  10 D of the electric element  100  and the other end connected with the positive terminal  111  of the CPU  110 . A lead wire  124  has one end connected with the cathode electrode  20 F of the electric element  100  and the other end connected with the negative terminal  112  of the CPU  110 . 
     With this configuration, the DC current I output from the positive terminal  91  of a power source  90  passes through the lead wire  121  to the anode electrode  10 C of the electric element  100 , and then passes the side anode electrode  10 A, conductive plates  11 ,  12 , side anode electrode  10 B and anode electrode  10 D in this order inside the electric element  100 . The DC current I flows from the anode electrode  10 D to the CPU  110  through the lead wire  123  and positive terminal  111 . 
     This passage allows the DC current I to be supplied as a power source current to the CPU  110 . The CPU  110  is driven with the DC current I and outputs a return current Ir, which has the same magnitude as the DC current I, from the negative terminal  112 . 
     The return current Ir flows through the lead wire  124  to the cathode electrode  20 F of the electric element  100 , and passes the side cathode electrodes  20 C,  20 D, conductive plates  21  to  23 , side cathode electrodes  20 A,  20 B, and cathode electrode  20 E in this order inside the electric element  100 . The return current Ir then flows from the cathode electrode  20 E, through the lead wire  122  and negative terminal  92 , to the power source  90 . 
     Since the DC current I thus flows through the conductive plates  11 ,  12  from the power source  90  side to the CPU  110  side, while the return current Ir flows through the conductive plates  21  to  23  from the CPU  110  side to the power source  90  side, the effective inductance L of the electric element  100  decreases as discussed above. On the other hand, the effective capacitance C of the electric element  100  increases due to the four parallel-connected capacitors of the electric element  100 . 
     As a result, the impedance of the electric element  100  is reduced. 
     The CPU  110  is driven with the DC current I supplied from the power source  90  through the electric element  100 , and produces an unwanted high-frequency current. This unwanted high-frequency current leaks through the lead wire  123 ,  124  out to the electric element  100 . However, the low impedance of the electric element  100  as discussed above causes the unwanted high-frequency current to flow within circuitry made up of the electric element  100  and CPU  110 , thereby preventing the leakage from the electric element  100  toward the power source  90 . 
     Under circumstances where the operating frequency of the CPU  110  tends to shift toward high frequencies, it could be assumed that the CPU  110  is operated at approximately 1 GHz. In such a high operating frequency range, the electric element  100  functions as a noise filter for confining the unwanted high-frequency current, which is produced by the CPU  110  operating at the high operating frequency, within the vicinity of the CPU  110  under the condition that impedance of the electric element  100  is determined mainly by the effective inductance L that is reduced as discussed above. 
       FIG. 12  illustrates frequency-dependent attenuation characteristics S 21  in the electric element  100  shown in  FIG. 1 . In  FIG. 12 , the horizontal axis indicates frequencies, while the vertical axis indicates the attenuation characteristics S 21 . The attenuation characteristics S 21  shown in  FIG. 12  were obtained from a simulation with an electric element having five conductive plates connected to the side anode electrodes  10 A,  10 B and six conductive plates connected to the side cathode electrodes  20 A,  20 B,  20 C,  20 D. For information, the attenuation characteristics S 21  indicate how much the high-frequency currents, which were input from the CPU  110  to the electric element  100 , attenuate in the electric element  100 , on condition that the CPU  110  is set as an input side and the power source  90  is set as an output side. 
     Referring to  FIG. 12 , the attenuation characteristics S 21  decline with the frequency rise. At the frequency of 1000 MHz (1 GHz), the high-frequency current is attenuated to −150 dB or less. In short, the attenuation increases with an increase in frequency in the electric element  100 . Even if the frequency reaches 100 MHz or higher, the attenuation does not shrink, but becomes further greater as the frequency rises. 
     Thus, as the operating frequency of the CPU  110  shown in  FIG. 11  becomes higher, the impedance of the electric element  100  is reduced in conjunction with the decrease of the effective inductance L, and therefore the electric element  100  can improve its function as a noise filter for confining the unwanted high-frequency current produced by the CPU  110  within the vicinity of the CPU  110 . 
       FIG. 13  is a view illustrating the frequency dependence of impedance in the electric element  100  shown in  FIG. 1 . In  FIG. 13 , the horizontal axis indicates frequency, while the vertical axis indicates impedance. For information, the impedance in  FIG. 13  was obtained, using an electric element  100  with four terminals (two anodes and two cathodes), by converting from the attenuation characteristics S 21  with the following expression: 
                             [   S   ]     =       1       2   ⁢     Z   ^       +   1       ⁡     [           -   1           2   ⁢     Z   ^                 2   ⁢     Z   ^             -   1           ]                     Z   ^     =       Z   s       Z   o               }           (   5   )               
In this expression, Z 0  represents characteristic impedance.
 
     Referring to  FIG. 13 , the impedance declines with an increase in frequency. At the frequency of several hundreds of megahertz or higher, the impedance is reduced to 10 −3 (Ω) or lower. The impedance reaches 10 −6  (Ω) or lower at the frequency of 1000 MHz (1 GHz). 
     Conventional noise filters do not permit the impedance to reach 10 −3 (Ω) or lower at the frequency of hundreds of megahertz or higher, however, the electric element  100  of this invention enables the impedance to be significantly lower than 10 −3  (Ω) in a frequency range of several hundreds megahertz or higher. 
       FIG. 14  is another view illustrating the frequency dependence of impedance in the electric element  100  shown in  FIG. 1 . In  FIG. 14 , the horizontal axis indicates frequency, while the vertical axis indicates impedance. The impedance shown in  FIG. 14  was obtained from simulations with electric elements with one conductive plate for an anode and one conductive plate for a cathode and indicates how the variation of the ratio between a length and width of the anode conductive plate influences the characteristics of the element. The inductance component is great, and a self-resonant frequency appears on the order of 100 MHz. 
     The impedance shown in  FIG. 13  was obtained from the simulation with the electric element having five conductive plates for an anode and six conductive plates for a cathode, and length L 1  and width W 1  of conductive plates measure 15 mm by 13 mm. Because of this configuration, the effective inductance of the electric element is reduced with an increase of the mutual inductance, and therefore the impedance shown in  FIG. 13  declines. 
     In  FIG. 14 , the simulations for the impedances were performed using electric elements each having various sized anode conductive plates. The conductive plates are formed so as to have length L 2 , shown in  FIG. 3 , fixed to 10 mm and width W 2  changed variously. The curves k 1  to k 5  indicate the impedances of the electric elements with width W 2  of 4 mm, 6 mm, 8 mm, 10 mm and 12 mm, respectively. 
     As apparent from the results shown in  FIG. 14 , the impedances decline in all frequency ranges for the electric elements with the fixed length L 2  and differently widened widths W 2 . The impedances indicated by the curves k 4  and k 5  both having W 2 ≧L 2  are reduced to 0.3Ω or lower in a high-frequency range of 0.2 GHz or higher. 
     In the present invention, length L 2  and width W 2  of the overlap part  20  are set so as to be W 2 ≧L 2 . The value of W 2 /L 2  is set relatively large as the operating frequency of the CPU  110  relatively rises. This reduces the impedance of the electric element  100  in the high-frequency range. 
       FIG. 15  is yet another view illustrating the frequency dependence of the impedance in the electric element  100  shown in  FIG. 1 . In  FIG. 15 , the horizontal axis indicates frequency, while the vertical axis indicates impedance. For information, the impedances in  FIG. 15  were obtained, using an electric element  100  with four terminals (two anodes and two cathodes), by converting from the attenuation characteristics S 21  with expression (5). The curves k 6  to k 8  are experimental results indicating the frequency dependence of impedance (Z 21 ) in the electric element  100  when L 2 &gt;W 2 . Specifically, curves k 6 , k 7  and k 8  show the frequency dependence of impedance (Z 21 ) in electric elements  100  with L 2 =12 mm and W 2 =10 mm, L 2 =12 mm and W 2 =8 mm, and L 2 =12 mm and W 2 =5 mm, respectively. 
     As apparent from the results shown in  FIG. 15 , the impedance (Z 21 ) of the electric element  100  declines in a frequency range of 10 7  (Hz) or higher as length L 2  becomes longer than width W 2 . In other words, the longer length L 2  is than width W 2 , the more the electric element  100 , used in the operating state shown in  FIG. 11 , improves its noise filter function. When the electric element  100  is used as a noise filter, the relation of length L 2  and width W 2  are thus set so as to hold L 2 &gt;W 2 . 
       FIG. 16  is yet another view illustrating the frequency dependence of impedance in the electric element  100  shown in  FIG. 1 . In  FIG. 16 , the horizontal axis indicates frequency, while the vertical axis indicates impedance. For information, the impedances in  FIG. 16  were obtained, using electric elements  100  with four terminals (two anodes and two cathodes), by converting from reflection characteristics S 22  with expression (5). 
     Curve k 9  shows the frequency dependence of impedance (Z 22 ) of an electric element  100  with W 2 ≧L 2 . Curve k 10  shows the frequency dependence of impedance (Z 22 ) of an electric element  100  with L 2 &gt;W 2 . 
     Referring to  FIG. 16 , the impedances (Z 22 ) of the electric elements  100  show almost the same result in the frequency range of 4×10 6  (Hz) or lower even if the relation between length L 2  and width W 2  is set either W 2 ≧L 2  or L 2 ≧W 2 . On the other hand, the impedances (Z 22 ) of the electric elements  100  are reduced in the frequency range of 4×10 6  (Hz) or higher by setting the relation between length L 2  and width W 2  to be W 2 ≧L 2 . By setting length L 2  and width W 2  so as to be W 2 ≧L 2 , the electric element  100  used in the operating state shown in  FIG. 11  reflects less electric currents fed from the CPU  110 . Accordingly, when the electric element  100  is used as a capacitor, the relation of length L 2  and width W 2  is thus set to hold W 2 ≧L 2 . 
     The electric element  101  shown in  FIG. 10  is also used in the operating state shown in  FIG. 11  and has the same frequency dependence of the impedance shown in  FIGS. 15 and 16 . 
     As discussed above, the electric element  100  ( 101 ) is connected between the power source  90  and CPU  110 , and functions as a noise filter for confining the unwanted high-frequency current produced by the CPU  110  within the vicinity of the CPU  110  or as a capacitor for supplying the power source current to the CPU  110 . When the electric element  100  is connected between the power source  90  and CPU  110 , the conductive plates  11 ,  12 ,  21  to  23  are connected as transmission lines. In other words, the capacitor made up of the conductive plates  11 ,  12  connected to the anode electrodes  10 C,  10 D and the conductive plates  21  to  23  connected to the cathode electrodes  20 E,  20 F does not require terminals to be connected to the transmission line but using the conductive plates  11 ,  12 ,  21  to  23  as a part of the transmission lines. The conductive plates  11 ,  12 , therefore, are conductors used for allowing the DC current I output from the power source  90  to flow from the power source  90  side to the CPU  110  side, while the conductive plates  21  to  23  are conductors used for allowing the return current Ir to flow from the CPU  110  side to the power source  90  side. 
     Consequently, the equivalent series inductance can be reduced to a minimum. 
     In addition, the electric element  100  ( 101 ) is so configured that a current flowing in the conductive plates  11 ,  12  connected to the anode electrodes  10 C,  10 D, ( 120 ,  130 ) is directed opposite to a current flowing in the conductive plates  21  to  23  connected to the cathode electrodes  20 E,  20 F, thereby creating magnetic interference between the conductive plates  11 ,  12  and conductive plates  21  to  23 . Because of the magnetic interference, the mutual inductance between the conductive plates  11 ,  12  and conductive plates  21  to  23  reduces the self-inductance of the conductive plates  11 ,  12 . The reduction of the self-inductance of the conductive plates  11 ,  12  reduces the effective inductance of the electric element  100  ( 101 ), thus lowering the impedance of the electric element  100  ( 101 ). 
     The first characteristic feature of this invention discussed above is that the conductive plates  11 ,  12 ,  21  to  23 , which constitute electrodes of the capacitor, are connected as a part of the transmission lines. The second characteristic feature is that the current flowing through the conductive plates  11 ,  12  connected to the anode electrodes  10 C,  10 D and the current flowing in the opposite direction through the conductive plates  21  to  23  connected to the cathode electrodes  20 E,  20 F create magnetic interference between the conductive plates  11 ,  12  and conductive plates  21  to  23 , thereby making the effective inductance of the conductive plates  11 ,  12  smaller than the self-inductance of the conductive plates  11 ,  12 , therefore lowering the impedance of the electric element  100  ( 101 ). The third characteristic feature is that each of the conductive plates  11 ,  12  passing the DC current constituting an electric current from the power source is sandwiched by two conductive plates (conductive plates  21  and  22  or conductive plates  22  and  23 ) connected to ground potential. 
     The second characteristic feature is realized by adopting the structure in which the return current Ir from the CPU  110  flows to the conductive plates  21  to  23  placed in the electric element  100  ( 101 ). 
     The equivalent series inductance can be reduced to a minimum according to the first characteristic feature, and the unwanted high-frequency current can be confined in the vicinity of the CPU  110  according to the second characteristic feature. The third characteristic feature prevents noise generated by the electric element  100  ( 101 ) from leaking outside as well as preventing noise generated outside the electric element  100  ( 101 ) from affecting the electric element  100  ( 101 ). 
     Although all the dielectric layers  1  to  5  are composed of the same dielectric material (BaTiO 3 ) in the above embodiment, the present invention is not limited to this. The dielectric layers  1  to  5  can be composed of different dielectric materials on an individual basis. Alternatively, the dielectric layers  1  to  5  can be put into two groups each composed of the same material, but the materials are different to each other. Typically the dielectric layers  1  to  5  may be composed of one or more kinds of dielectric materials. Any dielectric material for forming the dielectric layers  1  to  5  preferably has the relative permittivities of 3000 or more. 
     In addition to BaTiO 3 , the dielectric layers may be composed of Ba(Ti, Sn)O 3 , Bi 4 Ti 3 O 12 , (Ba, Sr, Ca)TiO 3 , (Ba, Ca)(Zr, Ti)O 3 , (Ba, Sr, Ca)(Zr, Ti)O 3 , SrTiO 3 , CaTiO 3 , PbTiO 3 , Pb(Zn, Nb)O 3 , Pb(Fe, W)O 3 , Pb(Fe, Nb)O 3 , Pb(Mg, Nb)O 3 , Pb(Ni, W)O 3 , Pb(Mg, W)O 3 , Pb(Zr, Ti)O 3 , Pb(Li, Fe, W)O 3 , Pb 5 Ge 3 O 11  and CaZrO 3 , and so forth. 
     Although the anode electrodes  10 C,  10 D ( 120 ,  130 ), side anode electrodes  10 A,  10 B, conductive plates  11 ,  12 ,  21  to  23 , side cathode electrodes  20 A,  20 B,  20 C,  20 D and cathode electrodes  20 E,  20 F are composed of nickel (Ni) in the above embodiment, the present invention is not limited to this. The anode electrodes  10 C,  10 D, ( 120 ,  130 ), side anode electrodes  10 A,  10 B, conductive plates  11 ,  12 ,  21  to  23 , side cathode electrodes  20 A,  20 B,  20 C,  20 D and cathode electrodes  20 E,  20 F can be composed of any of silver (Ag), palladium (Pd), silver-palladium alloy (Ag—Pd), platinum (Pt), gold (Au), copper (Cu), rubidium (Ru) and tungsten (W). 
     Although the electric element  100  ( 101 ) comprises the dielectric layers  1  to  5  in the above embodiment, the present invention is not limited to this. The electric element  100  ( 101 ) does not need to comprise the dielectric layers  1  to  5 . Since magnetic interference could occur between the conductive plates  11 ,  12  and conductive plates  21  to  23  even without the dielectric layers  1  to  5 , the aforementioned mechanism can reduce the impedance of the electric element  100  ( 101 ). 
     Although the number of the conductive plates to be connected to the anode electrodes  10 C,  10 D ( 120 ,  130 ) is two (i.e. conductive plates  11 ,  12 ), while the number of the conductive plates to be connected to the cathode electrodes  20 E,  20 F is three (i.e. conductive plates  21 ,  22 ,  23 ) in the above embodiment, the present invention is not limited to this. The electric element  100  ( 101 ) can comprise n-number (n is a positive integer) of the conductive plates connected to the anode electrodes  10 C,  10 D ( 120 ,  130 ) and m-number (m is a positive integer) of the conductive plates connected to the cathode electrodes  20 E,  20 F. In this case, the electric element  100  ( 101 ) comprises j-number (j=m+n) of the dielectric layers. The magnetic interference to make the effective inductance small can be generated as long as there are at least one conductive plate connected to the anode electrodes  10 C,  10 D, ( 120 ,  130 ) and at least one conductive plate connected to the cathode electrodes  20 E,  20 F. 
     In the present invention, the number of the conductive plates connected to the anode electrodes  10 C,  10 D ( 120 ,  130 ) and the number of the conductive plates connected to the cathode electrodes  20 E,  20 F are increased with an increase of the electric current flowing in the electric element  100  ( 101 ). Since the conductive plates connected to the anode electrodes  10 C,  10 D ( 120 ,  130 ) and the conductive plates connected to the cathode electrodes  20 E,  20 F are connected between two anode electrodes (i.e.  10 C and  10 D or  120  and  130 ), or between two cathode electrodes (i.e.  20 E and  20 F) in parallel, the addition of the conductive plates connected to the anode electrodes  10 C,  10 D ( 120 ,  130 ) and the conductive plates connected to the cathode electrodes  20 E,  20 F can increase the amount of electric current flowing in the electric element  100  ( 101 ). 
     In order to relatively reduce impedance of the electric element  100  ( 101 ), the number of the conductive plates connected to the anode electrodes  10 C,  10 D ( 120 ,  130 ) and the number of the conductive plates connected to the cathode electrodes  20 E,  20 F are increased in the present invention. Because the addition of the conductive plates connected to the anode electrodes  10 C,  10 D ( 120 ,  130 ) and the conductive plates connected to the cathode electrodes  20 E,  20 F provides additional capacitors to be connected in parallel, thereby increasing the effective capacitance of the electric element  100  ( 101 ), therefore lowering the impedance. 
     Although the conductive plates  11 ,  12  are disposed parallel with the conductive plates  21  to  23  in the above embodiment, the present invention is not limited to this. The conductive plates  11 ,  12 ,  21  to  23  can be disposed so that the distance between the conductive plates  11 ,  12  and the conductive plates  21  to  23  varies along the longitudinal direction DR 1 . 
     Although the electric element  100  ( 101 ) is connected to the CPU  110  in the above embodiment, the present invention is not limited to this. The electric element  100  ( 101 ) can be connected to any electrical load circuit as long as the electrical load circuit operates at a predetermined frequency. 
     Although the electric element  100  ( 101 ) is used as a noise filter for confining the unwanted high-frequency current produced by the CPU  110  within the vicinity of the CPU  110  in the above embodiment, the present invention is not limited to this. Since the electric element  100  ( 101 ) includes four capacitors connected in parallel as discussed above, the electric element  100  ( 101 ) also can be used as a capacitor. 
     More concretely, the electric element  100  ( 101 ) can be used in notebook computers, CD-RW/DVD recorders and players, game machines, information appliances, digital cameras, in-vehicle electric equipment, in-vehicle digital equipment, MPU peripheral circuitry and DC/DC converters and so forth. 
     Electric elements that are adopted in notebook computers and CD-RW/DVD recorders and players as a capacitor, but function as a noise filter, arranged between the power source  90  and CPU  110 , for confining the unwanted high-frequency current produced by the CPU  110  within the vicinity of the CPU  110  are grouped with the electric element  100  ( 101 ) of the present invention. 
     According to the above-described first embodiment, the electric element  100  comprises conductive plates  11 ,  12 , conductive plates  21  to  23  alternately disposed with the conductive plates  11 ,  12 , a side anode electrode  10 A and an anode electrode  10 C connected to one end of the conductive plates  11 ,  12 , a side anode electrode  10 B and an anode electrode  10 D connected to the other end of the conductive plates  11 ,  12 , side cathode electrodes  20 A,  20 B and a cathode electrode  20 E connected to the conductive plates  21  to  23  in the proximity of one end of the conductive plates  21  to  23 , and side cathode electrodes  20 C,  20 D and a cathode electrode  20 F connected to the conductive plates  21  to  23  in the proximity of the other end of the conductive plates  21  to  23 . The electric current flows in order from the anode electrode  10 C, side anode electrode  10 A, conductive plates  11 ,  12 , side anode electrode  10 B to anode electrode  10 D, while the return current flows in order from the cathode electrode  20 F, side cathode electrodes  20 C,  20 D, conductive plates  21  to  23 , side cathode electrodes  20 A,  20 B to cathode electrode  20 E. With this configuration, the return current flowing in the conductive plates  21  to  23  causes mutual inductance between the conductive plates  11 ,  12  and conductive plates  21  to  23 , thereby making the effective inductance of the conductive plates  11 ,  12  smaller than the self-inductance of the conductive plates  11 ,  12 . 
     The electric element  101  comprises conductive plates  11 ,  12 , conductive plates  21 ,  22  alternately disposed with the conductive plates  11 ,  12 , an anode electrode  120  connected to one end of the conductive plates  11 ,  12 , an anode electrode  130  connected to the other end of the conductive plates  11 ,  12 , a side cathode electrodes  20 A,  20 B and a cathode electrode  20 E connected to the conductive plates  21 ,  22  in the proximity of one end of the conductive plates  21 ,  22 , and side cathode electrodes  20 C,  20 D and a cathode electrode  20 F connected to the conductive plates  21 ,  22  in the proximity of the other end of the conductive plates  21 ,  22 . The electric current flows in order from the anode electrode  120 , through the conductive plates  11 ,  12 , to the anode electrode  130 , while the return current flows in order from the cathode electrode  20 F, through the side cathode electrodes  20 C,  20 D, conductive plates  21 ,  22 , side cathode electrodes  20 A,  20 B to the cathode electrode  20 E. With this configuration, the return current flowing in the conductive plates  21 ,  22  causes mutual inductance between the conductive plates  11 ,  12  and conductive plates  21 ,  22 , thereby making the effective inductance of the conductive plates  11 ,  12  smaller than the self-inductance of the conductive plates  11 ,  12 . 
     According to the present invention, the impedance can be reduced with the decrease of the inductance. 
     The Second Embodiment 
       FIG. 17  is a schematic view illustrating the structure of an electric element according to the second embodiment. Referring to  FIG. 17 , the electric element  200  of the second embodiment includes conductive plates  201 ,  202  instead of the conductive plates  21 ,  22  of the electric element  101  shown in  FIG. 10  and the same components as those of the electric element  101 . 
     The conductive plates  201 ,  202  are composed of nickel (Ni). The conductive plate  201  is placed on a principal surface of a dielectric layer  1 , while the conductive plate  202  is placed on a principal surface of a dielectric layer  3 . The conductive plates  201 ,  202  are connected to side cathode electrodes  20 A,  20 C on the front face  100 D of the electric element  200  and side cathode electrodes  20 B,  20 D on the rear face  100 E. 
       FIGS. 18A to 18E  are plan views of the dielectric layers  1 ,  2  and conductive plates  11 ,  201  shown in  FIG. 17  and a bottom view of the electric element  200 .  FIG. 18A  is a plan view of the dielectric layer  1 ,  FIG. 18B  is a plan view of the conductive plate  11 ,  FIG. 18C  is a plan view of the dielectric layer  2 ,  FIG. 18D  is a plan view of the conductive plate  201 , and  FIG. 18E  is a bottom view of the electric element  200 . 
     The dielectric layers  1 ,  2  have length L 1  and width W 1  (see  FIGS. 18A and 18C ) as discussed above. The conductive plate  11  has length L 1  and width W 2  (see  FIG. 18B ) as discussed above. The dielectric layers  3  to  5  are in the same form of a flat plate as the dielectric layers  1 ,  2 , while the conductive plate  12  is in the same form of a flat plate as the conductive plate  11 . 
     The conductive plate  201  has length L 2  and width W 2 . Length L 2  is shorter than length L 1 , and width W 2  is narrower than width W 1 . The conductive plate  201  has extending portions  201 A,  201 B,  201 C,  201 D. The extending portions  201 A,  201 B are located closer to one side  201 E than the midpoint of the conductive plate  201  in the longitudinal direction, while the extending portions  201 C,  201 D are located closer to the other side  201 F than the midpoint of the conductive plate  201  in the longitudinal direction. The provision of the extending portions  201 A,  201 B,  201 C,  201 D widens the width from the extending portion  201 A to  201 B and from the extending portion  201 C to  201 D of the conductive plate  201  to width W 1 . This configuration allows the extending portions  201 A,  201 B,  201 C,  201 D to be connected to the side cathode electrodes  20 A,  20 B,  20 C,  20 D, respectively. The conductive plate  202  shown in  FIG. 17  is in the same form of a flat plate as the conductive plate  201  shown in  FIG. 18D . 
     On the bottom face of the electric element  200 , an anode electrode  120  (strip electrode  122 ) is disposed on one side of the electric element  200 , while an anode electrode  130  (strip electrode  132 ) is disposed on the other side of the electric element  200 . A cathode electrode  20 E is disposed between the anode electrode  120  and  130  but closer to the anode electrode  120  than the midpoint between the anode electrodes  120  and  130 , while a cathode electrode  20 F is disposed between the anode electrodes  120  and  130  but closer to the anode electrode  130  than the midpoint between the anode electrode  120  and anode electrode  130  (see  FIG. 18E ). 
     Due to such plane shapes of the conductive plates  11 ,  12 ,  201 ,  202  and the dielectric layers  1  to  5  as shown in  FIGS. 18A to 18E , in the electric element  200 , the anode electrode  120  is connected to the conductive plates  11 ,  12  on the side face  100 A of the electric element  200 , the anode electrode  130  is connected to the conductive plates  11 ,  12  on the side face  100 B, opposite to the side face  100 A, of the electric element  200 , the side cathode electrodes  20 A,  20 C are connected to the conductive plates  201 ,  202  on the front face  100 D, approximately perpendicular to the side faces  100 A,  100 B, of the electric element  200 , and the side cathode electrodes  20 B,  20 D are connected to the conductive plates  201 ,  202  on the rear face  100 E, approximately perpendicular to the side faces  100 A,  100 B, of the electric element  200 . 
     The electric element  200  shown in  FIG. 17  has the frequency dependence of the impedance shown in the aforementioned  FIGS. 15 and 16 . Therefore, when the electric element  200  is used as a noise filter, the relation of length L 2  and width W 2  is set to be L 2 &gt;W 2 . When the electric element  200  is used as a capacitor, the relation of length L 2  and width W 2  is set to be W 2 ≧L 2 . 
     As to the other structure, the electric element  200  is the same as the electric element of the first embodiment. 
     The Third Embodiment 
       FIG. 19  is a schematic view illustrating the structure of an electric element according to the third embodiment. Referring to  FIG. 19 , the electric element  300  of the third embodiment includes conductive plates  301 ,  302  instead of the conductive plates  11 ,  12  of the electric element  101  shown in  FIG. 10 , conductive plates  311 ,  312  instead of the conductive plates  21 ,  22 , an anode electrode  320  instead of the side anode electrode  10 A and anode electrode  10 C, an anode electrode  330  instead of the side anode electrode  10 B and anode electrode  10 D, a cathode electrode  340  instead of the side cathode electrodes  20 A,  20 B and cathode electrode  20 E, a cathode electrode  350  instead of the side cathode electrodes  20 C,  20 D and cathode electrode  20 F. The other components are the same as those of the electric element  101 . 
     The conductive plate  301  is placed on a principal surface of the dielectric layer  2 , while the conductive plate  302  is placed on a principal surface of the dielectric layer  4 . The conductive plate  311  is placed on a principal surface of the dielectric layer  1 , while the conductive plate  312  is placed on a principal surface of the dielectric layer  3 . These conductive plates  301 ,  302 ,  311 ,  312  are composed of nickel (Ni). 
     The anode electrode  320  is disposed on a part of the side face  100 A, bottom face  100 C, rear face  100 E and top face  100 F of the electric element  300 , and connected to one end of the conductive plates  301 ,  302 . More specifically, the anode electrode  320  includes a side anode electrode  321  and strip electrodes  322  to  324 . The side anode electrode  321  is arranged on the side face  100 A of the electric element  300  and connected to one end of the conductive plates  301 ,  302 . The strip electrodes  322 ,  323 ,  324  are arranged on the bottom face  100 C, rear face  100 E, top face  100 F, respectively, of the electric element  300 . 
     The anode electrode  330  is disposed on a part of the side face  100 B, bottom face  100 C, front face  100 D and top face  100 F of the electric element  300 , and connected to the other end of the conductive plates  301 ,  302 . More specifically, the anode electrode  330  includes a side anode electrode  331  and strip electrodes  332  to  334 . The side anode electrode  331  is arranged on the side face  100 B of the electric element  300  and connected to the other end of the conductive plates  301 ,  302 . The strip electrodes  332 ,  333 ,  334  are arranged on the bottom face  100 C, front face  100 D, top face  100 F, respectively, of the electric element  300 . 
     The cathode electrode  340  is disposed on a part of the side face  100 A, bottom face  100 C, front face  100 D and top face  100 F of the electric element  300 , and connected to one end of the conductive plates  311 ,  312 . More specifically, the cathode electrode  340  includes a side cathode electrode  341  and strip electrodes  342  to  344 . The side cathode electrode  341  is arranged on the side face  100 A of the electric element  300  and connected to one end of the conductive plates  311 ,  312 . The strip electrodes  342 ,  343 ,  344  are arranged on the bottom face  100 C, front face  100 D, top face  100 F, respectively, of the electric element  300 . 
     The cathode electrode  350  is disposed on a part of the side face  100 B, bottom face  100 C, rear face  100 E and top face  100 F of the electric element  300 , and connected to the other end of the conductive plates  311 ,  312 . More specifically, the cathode electrode  350  includes a side cathode electrode  351  and strip electrodes  352  to  354 . The side cathode electrode  351  is arranged on the side face  100 B of the electric element  300  and connected to the other end of the conductive plates  311 ,  312 . The strip electrodes  352 ,  353 ,  354  are disposed on the bottom face  100 C, rear face  100 E, top face  100 F, respectively, of the electric element  300 . 
       FIGS. 20A to 20E  are plan views of the dielectric layers  1 ,  2  and conductive plates  301 ,  311  shown in  FIG. 19  and a bottom view of the electric element  300  shown in  FIG. 19 .  FIG. 20A  is a plan view of the dielectric layer  1 ,  FIG. 20B  is a plan view of the conductive plate  301 ,  FIG. 20C  is a plan view of the dielectric layer  2 ,  FIG. 20D  is a plan view of the conductive plate  311 , and  FIG. 20E  is a bottom view of the electric element  300 . 
     The dielectric layers  1 ,  2  have the aforementioned length L 1  and width W 1  (see  FIGS. 20A ,  20 C). The dielectric layers  3  to  5  have the same shape and dimensions as the dielectric layers  1 ,  2 . 
     The conductive plate  301  has an approximately rectangular plane. The conductive plate  301  has length L 2  along in a lateral direction of the rectangle and width W 2  in a vertical direction of the rectangle. Length L 2  is shorter than length L 1 , while width W 2  is narrower than width W 1 . In addition, the conductive plate  301  has two extending portions  301 A,  301 B. The two extending portions  301 A,  301 B are provided at opposite ends on one of two diagonal lines of the rectangle (see  FIG. 20B ). This configuration allows the extending portions  301 A and  301 B to be connected to the side anode electrode  321  of the anode electrode  320  and the side anode electrode  331  of the anode electrode  330 , respectively. The conductive plate  302  has the same shape and dimensions as the conductive plate  301 . 
     The conductive plate  311  has an approximately rectangular plane. The conductive plate  311  has length L 2  in a lateral direction of the rectangle and width W 2  in a vertical direction of the rectangle. In addition, the conductive plate  311  has two extending portions  311 A,  311 B. The two extending portions  311 A,  311 B are provided at opposite ends on the other diagonal line of the two diagonal lines of the rectangle (see  FIG. 20D ). This configuration allows the extending portions  311 A and  311 B to be connected to the side cathode electrode  341  of the cathode electrode  340  and the side cathode electrode  351  of the cathode electrode  350 , respectively. The conductive plate  312  has the same shape and dimensions as the conductive plate  311 . 
     The anode electrode  320  (strip electrode  322 ), anode electrode  330  (strip electrode  322 ), cathode electrode  340  (strip electrode  342 ) and cathode electrode  350  (strip electrode  352 ) are located in four corners, respectively, of the bottom face  100 C of the electric element  300 . The two anode electrodes  320 ,  330  are disposed at the opposite ends on one of the two diagonal lines of the rectangle, while the two cathode electrodes  340 ,  350  are disposed at the opposite ends on the other diagonal line of the two diagonal lines of the rectangle (see  FIG. 20E ). 
     Due to such plane shapes of the conductive plates  301 ,  302 ,  311 ,  312  and dielectric layers  1  to  5  as shown in  FIGS. 20A to 20E , in the electric element  300 , the anode electrode  320  is connected to the conductive plates  301 ,  302  on the side face  100 A of the electric element  300 , while the anode electrode  330  is connected to the conductive plates  301 ,  302  on the side face  100 B, opposite to the side face  100 A, of the electric element  300 . The cathode electrode  340  is connected to the conductive plates  311 ,  312  on the side face  100 A of the electric element  300 , while the cathode electrode  350  is connected to the conductive plates  311 ,  312  on the side face  100 B of the electric element  300 . 
     The electric element  300  shown in  FIG. 19  has the frequency dependence of the impedance shown in aforementioned  FIGS. 15 and 16 . Therefore, when the electric element  300  is used as a noise filter, the relation of length L 2  and width W 2  is set so as to be L 2 &gt;W 2 . When the electric element  300  is used as a capacitor, the relation of length L 2  and width W 2  is set so as to be W 2 ≧L 2 . 
     As to the other structure, the electric element  300  is the same as the electric element of the first embodiment. 
     The Fourth Embodiment 
       FIG. 21  is a schematic view illustrating the structure of an electric element according to the fourth embodiment. Referring to  FIG. 21 , the electric element  400  of the fourth embodiment includes conductive plates  401 ,  402  instead of the conductive plates  11 ,  12  of the electric element  101  shown in  FIG. 10 , conductive plates  411 ,  412  instead of the conductive plates  21 ,  22 , an anode electrode  420  instead of the side anode electrode  10 A and anode electrode  10 C, an anode electrode  430  instead of the side anode electrode  10 B and anode electrode  10 D, a cathode electrode  440  instead of the side cathode electrodes  20 A,  20 B and cathode electrode  20 E, a cathode electrode  450  instead of the side cathode electrodes  20 C,  20 D and cathode electrode  20 F. The other components are the same as those of the electric element  101 . 
     The conductive plate  401  is placed on a principal surface of the dielectric layer  2 , while the conductive plate  402  is placed on a principal surface of the dielectric layer  4 . The conductive plate  411  is placed on a principal surface of the dielectric layer  1 , while the conductive plate  412  is placed on a principal surface of the dielectric layer  3 . These conductive plates  401 ,  402 ,  411 ,  412  are composed of nickel (Ni). 
     The anode electrode  420  is disposed on the front face  100 D, bottom face  100 C and top face  100 F of the electric element  400  and connected to the conductive plates  401 ,  402  in the proximity of one end of the conductive plates  401 ,  402 . The anode electrode  430  is disposed on the front face  100 D, bottom face  100 C and top face  100 F of the electric element  400  and connected to the conductive plates  401 ,  402  in the proximity of the other end of the conductive plates  401 ,  402 . 
     The cathode electrode  440  is disposed on the rear face  100 E, bottom face  100 C and top face  100 F of the electric element  400  and connected to the conductive plates  411 ,  412  in the proximity of one end of the conductive plates  411 ,  412 . The cathode electrode  450  is disposed on the rear face  100 E, bottom face  100 C and top face  100 F of the electric element  400  and connected to the conductive plates  411 ,  412  in the proximity of the other end of the conductive plates  411 ,  412 . 
       FIGS. 22A to 22E  are plan views of the dielectric layers  1 ,  2  and conductive plates  401 ,  411  shown in  FIG. 21  and a bottom view of the electric element  400  shown in  FIG. 21 .  FIG. 22A  is a plan view of the dielectric layer  1 ,  FIG. 22B  is a plan view of the conductive plate  401 ,  FIG. 22C  is a plan view of the dielectric layer  2 ,  FIG. 22D  is a plan view of the conductive plate  411 , and  FIG. 22E  is a bottom view of the electric element  400 . 
     The dielectric layers  1 ,  2  have the aforementioned length L 1  and width W 1  (see  FIGS. 22A ,  22 C). The dielectric layers  3  to  5  have the same shape and dimensions as the dielectric layers  1 ,  2 . 
     The conductive plate  401  has an approximately rectangular plane. The conductive plate  401  has length L 2  in a lateral direction of the rectangle and width W 2  in a vertical direction of the rectangle. Length L 2  is shorter than length L 1 , while width W 2  is narrower than width W 1 . In addition, the conductive plate  401  includes two extending portions  401 A,  401 B. The two extending portions  401 A,  401 B are provided on one of two sides in the lateral direction of the rectangle. In other words, the two extending portions  401 A,  401 B are formed on the same side (see  FIG. 22B ). This configuration allows the extending portions  401 A,  401 B to be connected to the anode electrodes  420 ,  430 , respectively. The conductive plate  402  has the same shape and dimensions as the conductive plate  401 . 
     The conductive plate  411  has an approximately rectangular plane. The conductive plate  411  has length L 2  in a lateral direction of the rectangle and width W 2  in a vertical direction of the rectangle. In addition, the conductive plate  411  has two extending portions  411 A,  411 B. The two extending portions  411 A,  411 B are provided on the other side of two sides along the lateral direction of the rectangle. In other words, the two extending portions  411 A,  411 B are provided on the side opposite to the side provided with two extending portions  401 A,  401 B of the conductive plate  401  (see  FIG. 22D ). This configuration allows the extending portions  411 A,  411 B to be connected to the cathode electrodes  440 ,  450 , respectively. The conductive plate  412  has the same shape and dimensions as the conductive plate  411 . 
     The anode electrode  420 , anode electrode  430 , cathode electrode  440  and cathode electrode  450  are arranged separately near four corners, respectively, on the bottom face  100 C of the electric element  400 . The two anode electrodes  420 ,  430  are located along one side out of two sides of the rectangle, while the two cathode electrodes  440 ,  450  are located along the other side out of two sides of the rectangle (see  FIG. 22E ). 
     Due to such plane shapes of the conductive plates  401 ,  402 ,  411 ,  412  and dielectric layers  1  to  5  as shown in  FIGS. 22A to 22E , in the electric element  400 , the anode electrodes  420 ,  430  are connected to the conductive plates  401 ,  402  on the front face  100 D of the electric element  400 , while the cathode electrodes  440 ,  450  are connected to the conductive plates  411 ,  412  on the rear face  100 E of the electric element  400 . 
     The electric element  400  shown in  FIG. 21  has the frequency dependence of the impedance shown in aforementioned  FIGS. 15 and 16 . Therefore, when the electric element  400  is used as a noise filter, the relation of the length L 2  and width W 2  is set so as to be L 2 &gt;W 2 . When the electric element  400  is used as a capacitor, the relation of the length L 2  and width W 2  is set so as to be W 2 ≧L 2 . 
     As to the other structure, the electric element  400  is the same as the electric element of the first embodiment. 
     Exemplary Modifications 
       FIG. 23  is a schematic view illustrating the first modification of the electric element according to the embodiments of the present invention. Referring to  FIG. 23 , the electric element  500  comprises conductive wires  501  to  503 ,  511 ,  512 , anode electrodes  504 ,  505 , and cathode electrodes  513 ,  514 . 
     The conductive wires  501  to  503  are connected approximately parallel between the anode electrodes  504 ,  505 . The conductive wires  511 ,  512  are connected approximately parallel between the cathode electrodes  513 ,  514 . The conductive wire  511  is located between the conductive wires  501 ,  502 , while the conductive wire  512  is located between the conductive wires  502 ,  503 . Consequently, the conductive wires  501  to  503 ,  511 ,  512  are disposed approximately parallel in one plane. 
       FIG. 24  is a plan view illustrating the electric element  500  shown in  FIG. 23 . Referring to  FIG. 24 , the conductive wires  501  to  503  have length L 3 , and the conductive wires  511 ,  512  have length L 4 . Length L 3  may be 15 mm, and length L 4  may be 10 mm, for example. 
     The space between the conductive wire  501  and conductive wire  511  is set at d 1 . The space d 1  may be several hundreds of micrometers, for example. The spaces between the conductive wire  511  and conductive wire  502 , between the conductive wire  502  and conductive wire  512 , and between the conductive wire  503  and conductive wire  512  are also set at d 1 . 
     A DC current flows through the conductive wires  501  to  503  in the direction of arrow  506 , while flowing through the conductive wires  511 ,  512  in the direction of arrow  507 . The self-inductance of the conductive wires  501  to  503  is reduced by the mutual inductance occurring between the conductive wires  501  to  503  and conductive wire  511  or  512 , thereby making the effective inductance smaller than the self-inductance. As a result, the impedance of the electric element  500  is lowered. 
       FIG. 25  is a schematic view illustrating the second modification of the electric element according to the embodiment of the present invention. Referring to  FIG. 25 , the electric element  600  comprises conductive wires  601  to  603 ,  611  to  613 , anode electrodes  604 ,  605 , and cathode electrodes  614 ,  615 . 
     The conductive wires  601  to  603  are connected approximately parallel between the anode electrodes  604  and  605 . The conductive wires  611  to  613  are connected approximately parallel between the cathode electrodes  614  and  615 . 
       FIGS. 26A and 26B  are side views illustrating the electric element  600  shown in  FIG. 25 .  FIG. 26A  is a side view of the electric element  600  viewed from direction A in  FIG. 25 , while  FIG. 26B  is a side view of the electric element  600  viewed from direction B in  FIG. 25 . In  FIG. 26B , the anode electrodes  604 ,  605  and cathode electrodes  614 ,  615  are omitted. 
     Referring to  FIGS. 26A and 26B , each of the conductive wires  603 ,  613  has length L 3 . The conductive wires  611  to  613  are opposed to the conductive wires  601  to  603 , respectively. The space between conductive wires  601  to  603  and conductive wires  611  to  613  is set at d 2 . The space d 2  may be several hundreds of micrometers, for example. 
     The space between the conductive wires  601  and  602  is set at d 3 . The space d 3  may be several hundreds of micrometers, for example. The spaces between the conductive wires  602  and  603 , between the conductive wires  611  and  612 , and between the conductive wires  612  and  613  are also set at d 3 . 
     In the electric element  600 , the conductive wires  601  to  603  connected to the anode electrodes  604 ,  605  are arranged on a different plane from the conductive wires  611  to  613  connected to the cathode electrode  614 ,  615 . 
     A DC current flows through the conductive wires  601  to  603  in the direction of arrow  606 , while a DC current flows through the conductive wires  611  to  613  in the direction of arrow  607 . The DC currents flowing in the opposite directions cause the mutual inductance between the conductive wires  601  to  603  and conductive wires  611  to  613 , which making the self-inductance of the conductive wires  601  to  603  small, and therefore the effective inductance is reduced. As a result, the impedance of the electric element  600  is lowered. 
       FIG. 27  is a schematic view illustrating the third modification of the electric element according to the embodiments of the present invention.  FIGS. 28A and 28B  are a plan view and a side view, respectively, illustrating the electric element shown in  FIG. 27 .  FIG. 28A  is a plan view viewed from direction C in  FIG. 27 , and  FIG. 28B  is a side view viewed from direction B in  FIG. 27 . 
     Referring to  FIGS. 27 ,  28 A and  28 B, the electric element  700  includes the conductive wires  601  to  603  and anode electrodes  604 ,  605 , of the electric element  600  in  FIG. 25 , shifted in a direction perpendicular to the direction of length L 3 . When the conductive wires  601  to  603  and conductive wires  611  to  613  are viewed in one plane, the conductive wires  601 ,  602  are arranged between the conductive wires  611  and  612  and between the conductive wires  612  and  613 , respectively (see  FIG. 28A ). 
     In the electric element  700 , a DC current flows in the conductive wires  601  to  603  in the opposite direction to a DC current flowing in the conductive wires  611  to  613 . Because the conductive wires  601 ,  602  are arranged between the conductive wires  611  and  612 , and between the conductive wires  612  and  613 , respectively, in one plane, the self-inductance of the conductive wire  601  is reduced by the mutual inductance generated between the conductive wire  601  and conductive wires  611 ,  612 . The effective inductance of the conductive wire  602  becomes lower than the self-inductance by the mutual inductance generated between the conductive wire  602  and conductive wires  612 ,  613 . 
     As a result, the effective inductance in the electric element  700  can be reduced, and therefore the impedance is lowered. 
       FIG. 29  is a schematic view illustrating the fourth modification of the electric element according to the embodiments of the present invention.  FIG. 30  is a plan view of the electric element  800  viewed from direction C in  FIG. 29 . Referring to  FIGS. 29 and 30 , the electric element  800  includes the conductive wires  601  to  603  and anode electrodes  604 ,  605  of the electric element  600  in  FIG. 25 , rotated by a predetermined angle θ (−90 degrees≦θ≦90 degrees) within a plane parallel to a plane including the conductive wires  611  to  613  and cathode electrodes  614 ,  615 . The θ is a degree with respect to a direction, from the left end to right end of the conductive wires  611  to  613  in  FIG. 30 , which is defined as zero degree. 
     In the electric element  800 , a DC current flows through the conductive wires  601  to  603  in the direction of arrow  608 , while a DC current flows through the conductive wires  611  to  613  in the direction of arrow  607 . The DC current flowing through the conductive wires  601  to  603  forms an angle 180-θ with the DC current flowing through the conductive wires  611  to  613 . Because the angle 180-θ is set in a range from 90 degrees to 270 degrees, magnetic interference between the conductive wires  601  to  603  and conductive wires  611  to  613  occurs, and therefore the magnetic flux produced by the DC current flowing in the conductive wires  601  to  603  is reduced by the magnetic flux produced by the DC current flowing in the conductive wires  611  to  613 . 
     Thus, the effective inductance of the conductive wires  601  to  603  is reduced to be smaller than the self-inductance by the mutual inductance generated between the conductive wires  601  to  603  and conductive wires  611  to  613 . As a result, the smaller effective inductance of the electric element  800  causes the impedance to be lowered. 
     In the present invention, the DC current flowing in the conductive wires  601  to  603  and the DC current flowing in the conductive wires  611  to  613  are directed so as to intersect with each other, if viewed in one plane, and therefore the magnetic flux produced by the DC current flowing in the conductive wires  601  to  603  is reduced by the magnetic flux produced by the DC current flowing in the conductive wires  611  to  613 . 
     The electric element  500  ( 600 ,  700 ,  800 ) connected between the power source  90  and CPU  110 , is used as a substitute for the electric element  100 . The anode electrode  504  ( 604 ) is connected to the lead wire  121 , the anode electrode  505  ( 605 ) is connected to the lead wire  123 , the cathode electrode  513  ( 614 ) is connected to the lead wire  122 , and the cathode electrode  514  ( 615 ) is connected to the lead wire  124 . The cathode electrodes  513 ,  514  ( 614 ,  615 ) are connected to ground potential. 
     In such the electric element  500  ( 600 ,  700 ,  800 ), a DC current from the power source  90  flows from the anode electrode  504  ( 604 ) to the anode electrode  505  ( 605 ), while a return current from the CPU  110  flows from the cathode electrode  514  ( 615 ) to the cathode electrode  513  ( 614 ). 
     As a result, the effective inductance of the electric element  500  ( 600 ,  700 ,  800 ) is reduced, therefore lowering the impedance. In addition, the electric element  500  ( 600 ,  700 ,  800 ) causes an unwanted high-frequency current produced by the CPU  110  to flow within circuitry made up of the electric element and the CPU  110  to confine the unwanted high-frequency current within the vicinity of the CPU  110 . 
     The electric element  500  ( 600 ,  700 ,  800 ) may further comprise dielectrics for covering the conductive wires  501  to  503 ,  511  and  512  ( 601  to  603 ,  611  to  613 ). 
     The electric element  500  ( 600 ,  700 ,  800 ) may comprise flat plate-like conductors instead of the conductive wires  501  to  503 ,  511 ,  512  ( 601  to  603 ,  611  to  613 ). 
     The Fifth Embodiment 
       FIG. 31  is a schematic view illustrating the structure of an electric circuit according to the fifth embodiment. Referring to  FIG. 31 , the electric circuit  1000  of the fifth embodiment comprises a power source  90 , an electric element  100 , a CPU  110 , and transmission lines  1120 ,  1130 ,  1140 ,  1150 . 
     The power source  90  includes a positive terminal  91  and a negative terminal  92 . The electric element  100  includes anode electrodes  101 ,  102  and cathode electrodes  103 ,  104 . The CPU  110  includes a positive terminal  111  and a negative terminal  112 . 
     The transmission line  1120  has one end connected to the positive terminal  91  of the power source  90  and the other end connected to the anode electrode  101  of the electric element  100 . The transmission line  1130  has one end connected to the anode electrode  102  and the other end connected to the positive terminal  111  of the CPU  110 . 
     The transmission line  1140  has one end connected to the negative terminal  92  of the power source  90  and the other end connected to the cathode electrode  103  of the electric element  100 . The transmission line  1150  has one end connected to the cathode electrode  104  of the electric element  100  and the other end connected to the negative terminal  112  of the CPU  110 . 
     In the electric circuit  1000 , overlap parts  20  of conductive plates  11 ,  12  and conductive plates  21  to  23  of the electric element  100  have length L 2  and width W 2  which are set so as to hold L 2 &gt;W 2 . The electric element  100  functions as a noise filter. 
     The power source  90  supplies a DC current I from the positive terminal  91  through the transmission line  1120  to the electric element  100 , and receives a return current Ir, which is fed from the electric element  100  through the transmission line  1140 , at the negative terminal  92 . 
     The electric element  100  receives the DC current I, which is supplied from the power source  90  via the transmission line  1120 , at the anode electrode  101 , and supplies the received DC current I from the anode electrode  102  through the transmission line  1130  to the CPU  110 . The electric element  100  further receives the return current Ir, which is supplied from the CPU  110  through the transmission line  1150 , at the cathode electrode  104 , and supplies the received return current Ir from the cathode electrode  103  through the transmission line  1140  to the power source  90 . In addition, the electric element  100  confines an unwanted high-frequency current transmitted through the transmission lines  1130 ,  1150  from the CPU  110  within circuitry made up of the electric element  100 , transmission lines  1130 ,  1150  and CPU  110  in the aforementioned manner, thereby preventing the unwanted high-frequency current from leaking toward the power source  90 . 
     The CPU  110  is driven with the DC current I supplied from the electric element  100  and operates at a predetermined frequency. The CPU  110  supplies the return current Ir through the transmission line  1150  to the electric element  100 . 
     In the above-described electric circuit  1000 , the electric element  100  supplies the DC current from the power source  90  to the CPU  110 , and confines the unwanted high-frequency current produced by the CPU  110  within the circuitry made up of the electric element  100 , the transmission lines  1130 ,  1150  and the CPU  110 , thereby preventing leakage of the unwanted high-frequency current toward the power source  90 . 
     Thus, the present invention can prevent the unwanted high-frequency current from leaking toward the power source. 
     In the fifth embodiment, any one of the electric elements  101 ,  200 ,  300 ,  400 ,  500 ,  600 ,  700  and  800  can be used instead of the electric element  100 . 
     The Sixth Embodiment 
       FIG. 32  is a schematic view illustrating the structure of an electric circuit according to the sixth embodiment. Referring to  FIG. 32 , the electric circuit  1100  of the sixth embodiment comprises a capacitor  160  and transmission lines  1170 ,  1180  in addition to the components of the electric circuit  1000  shown in  FIG. 31 . The other components are the same as these of the electric circuit  1000 . 
     The capacitor  160  includes an anode electrode  161  and a cathode electrode  162 . In the electric circuit  1100 , the transmission line  1130  has the other end connected to the anode electrode  161  of the capacitor  160 . The transmission line  1150  has the other end connected to the cathode electrode  162  of the capacitor  160 . 
     The transmission line  1170  has one end connected to the anode electrode  161  of the capacitor  160  and the other end connected to the positive terminal  111  of the CPU  110 . The transmission line  1180  has one end connected to the cathode electrode  162  of the capacitor  160  and the other end connected to the negative terminal  112  of the CPU  110 . 
     In the electric circuit  1100 , overlap parts  20  of the conductive plates  11 ,  12  and conductive plates  21  to  23  of the electric element  100  have length L 2  and width W 2  which are set so as to hold L 2 &gt;W 2 . The electric element  100  functions as a noise filter. 
     The power source  90  supplies a DC current I from the positive terminal  91  via the transmission line  1120  to the electric element  100 , and receives a return current Ir, which is supplied from the electric element  100  via the transmission line  1140 , at the negative terminal  92 . 
     The electric element  100  receives the DC current I, which is supplied from the power source  90  via the transmission line  1120 , at the anode electrode  101 , and supplies the received DC current I from the anode electrode  102  via the transmission line  1130  to the capacitor  160 . The electric element  100  also receives the return current Ir, which is supplied from the capacitor  160  via the transmission line  1150 , at the cathode electrode  104 , and supplies the received return current Ir from the cathode electrode  103  via the transmission line  1140  to the power source  90 . In addition, the electric element  100  confines an unwanted high-frequency current transmitted from the capacitor  160  via the transmission lines  1130 ,  1150  within circuitry made up of the electric element  100 , transmission lines  1130 ,  1150 , capacitor  160  and CPU  110  in the aforementioned manner, thereby preventing the unwanted high-frequency current from leaking toward the power source  90 . 
     The capacitor  160  stores the DC current supplied from the electric element  100  via the transmission line  1130 , and supplies the stored DC current through the transmission line  1170  to the CPU  110 . The capacitor  160  also supplies the return current Ir, which is supplied from the CPU  110  via the transmission line  1180 , through the transmission line  1150  to the electric element  100 . 
     The CPU  110  is driven with the DC current I supplied from the capacitor  160  and operates at a predetermined frequency. The CPU  110  then supplies the return current Ir to the capacitor  160  via the transmission line  1180 . 
       FIG. 33  is a conceptual illustration showing the electric element  100  shown in  FIG. 32  in an operating state. Referring to  FIG. 33 , the electric element  100  includes an anode electrode  10 C connected to the transmission line  1120  and an anode electrode  10 D connected to the transmission line  1130 . The electric element  100  further includes a cathode electrode  20 E connected to the transmission line  1140  and a cathode electrode  20 F connected to the transmission line  1150 . 
     With this configuration, a DC current I output from the positive terminal  91  of the power source  90  flows through the transmission line  1120  to the anode electrode  10 C of the electric element  100  and flows in the electric element  100  in order from the side anode electrode  10 A through the conductive plates  11 ,  12  and side anode electrode  10 B to the anode electrode  10 D. The DC current I then flows from the anode electrode  10 D via the transmission line  1130  and anode electrode  161  to the capacitor  160 . 
     The DC current I is stored in the capacitor  160  in such a way. The capacitor  160  supplies the stored DC current I to the CPU  110 . The CPU  110  is driven with the DC current I from the capacitor  160  and outputs a return current Ir equivalent in magnitude to the DC current I. The capacitor  160  supplies the return current Ir, which is supplied from the CPU  110 , to the electric element  100  through the transmission line  1150 . 
     The return current Ir then flows through the transmission line  1150  to the cathode electrode  20 F of the electric element  100 , and flows in the electric element  100  in order from the side cathode electrodes  20 C,  20 D through the conductive plates  21  to  23  and side cathode electrodes  20 A,  20 B to the cathode electrode  20 E. The return current Ir then flows from the cathode electrode  20 E through the transmission line  1140  and negative terminal  92  to the power source  90 . 
     Since the DC current I flows in the conductive plates  11 ,  12  from the power source  90  side to the CPU  110  side, while the return current Ir flows in the conductive plates  21  to  23  from the CPU  110  side to the power source  90  side in the electric element  100 , effective inductance L of the electric element  100  becomes small as discussed above. On the other hand, effective capacitance C of the electric element  100  becomes large due to the four capacitors being connected in parallel in the electric element  100 . Thus, the impedance of the electric element  100  is lowered. 
     The CPU  110  is driven with the DC current I supplied from the power source  90  through the electric element  100  and produces an unwanted high-frequency current. The unwanted high-frequency current is leaked through the transmission lines  1170 ,  1180  to the capacitor  160  and electric element  100 , however, the unwanted high-frequency current flows in circuitry made up of the electric element  100 , transmission lines  1130 ,  1150 , capacitor  160 , transmission lines  1170 ,  1180  and CPU  110  because of the low impedance of the electric element  100 , thereby preventing the unwanted high-frequency current from leaking from the electric element  100  toward the power source  90 . 
     Under circumstances where the operating frequency of the CPU  110  tends to shift toward high frequencies, it could be assumed that the CPU  110  operates at approximately 1 GHz. Even for such a high operating frequency range, because the impedance of the electric element  100  is determined mainly by the effective inductance L that is decreased as discussed above, the electric element  100  can confine the unwanted high-frequency current produced by the CPU  110  operating at a high operating frequency within the vicinity of the CPU  110 . In short, the electric element  100  prevents the leakage of the unwanted high-frequency current toward the power source. 
       FIG. 34  is a perspective view illustrating the structure of the capacitor  160  shown in  FIG. 32 . Referring to  FIG. 34 , the capacitor  160  includes a tantalum sintered body  163 , a dielectric oxide film  164 , conductive polymeric layer  165 , and a lead layer  166  in addition to the anode electrode  161  and cathode electrode  162 . The capacitor  160  in this embodiment has two terminals (i.e. one anode electrode and one cathode electrode), but may have three terminals (i.e. one anode electrode and two cathode electrodes) or four terminals (i.e. two anode electrodes and two cathode electrodes). 
     The dielectric oxide film  164  covers surfaces of the tantalum sintered body  163 . The conductive polymeric layer  165  composed of polypyrrole covers the dielectric oxide film  164 . The lead layer  166  including a carbon layer and a silver paint layer covers the conductive polymeric layer  165 . The carbon layer is formed so as to make contact with the conductive polymeric layer  165 , while the silver paint layer is formed so as to make contact with the carbon layer. 
     The anode electrode  161  is connected to the tantalum sintered body  163 , while the cathode electrode  113  is connected to the lead layer  166 . The tantalum sintered body  163  functions as an anode of the capacitor, and the conductive polymeric layer  165  functions as a cathode of the capacitor. 
     The capacitor having the structure shown in  FIG. 34  is referred to as POSCAP (Polymerized Organic Semiconductor Capacitors) and is a chip capacitor using the tantalum sintered body for an anode and the high-conductive polymeric (polypyrrole) layer for a cathode. This capacitor  160  (POSCAP) has a large capacity because the tantalum sintered body is porous. 
     This capacitor  160  (POSCAP) is fabricated in the following manner. At first, the dielectric oxide film  164  of several hundreds of angstroms is formed on surfaces of the tantalum sintered body  163 . Then, polypyrrole is polymerized to coat the dielectric oxide film  164 . This provides the conductive polymeric layer  165 . 
     Secondly, the carbon layer and silver paint layer are provided on the conductive polymeric layer  165  (polypyrrole layer). At last, the anode electrode  161  is connected to the tantalum sintered body  163  by resistance welding, and the cathode electrode  162  is connected to the lead layer  166  by silver adhesive. The capacitor  160  is thus completed. 
     Referring back to  FIG. 32 , the power source  90  supplies a DC current I through the transmission line  1120  to the electric element  100 . The electric element  100  allows the DC current I, which is supplied from the power source  90 , to flow from the anode electrode  101  ( 10 C), through the side anode electrode  10 A, conductive plates  11 ,  12 , side anode electrode  10 B and anode electrode  102  ( 10 D) to the transmission line  1130 . Through the transmission line  1130 , the DC current I is supplied to the capacitor  160 . 
     The capacitor  160  stores the DC current I supplied from the power source  90  via the electric element  100  and supplies the stored DC current I to the CPU  110  via the transmission line  1170 . 
     The CPU  110  is driven with the DC current I supplied from the capacitor  160  and operates at a predetermined frequency. The CPU  110  feeds a return current Ir of the DC current I through the transmission line  1180  to the capacitor  160 . With the operation of the CPU  110 , an unwanted high-frequency is generated and leaks through the transmission lines  1170 ,  1180  toward the capacitor  160 . 
     The capacitor  160  passes the return current Ir, which is supplied from the CPU  110 , through the cathode electrode  162 , lead layer  166  and conductive polymeric layer  165  to the transmission line  1150  that supplies the return current Ir to the electric element  100 . 
     The electric element  100  passes the return current Ir, which is supplied from the capacitor  160  through the transmission line  1150 , via the cathode electrode  104  ( 20 F), side cathode electrodes  20 C,  20 D, conductive plates  21  to  23 , side cathode electrodes  20 A,  20 B and cathode electrode  103  ( 20 E) to the transmission line  1140  that supplies the return current Ir to the power source  90 . 
     Since the DC current I flows in the conductive plates  11 ,  12  of the electric element  100  from the power source  90  side to the CPU  110  side, while the return current Ir flows in the conductive plates  21  to  23  of the electric element  100  from the CPU  110  side to the power source  90  side, the effective inductance of the conductive plates  11 ,  12  becomes smaller than the self-inductance due to the mutual inductance between the conductive plates  11 ,  12  and the conductive plates  21  to  23  as discussed above. As a result, the impedance of the electric element  100  decreases. 
     The unwanted high-frequency current leaks from the CPU  110  to the electric element  100  through the path made up of the transmission lines  1170 ,  1180 , capacitor  160  and transmission lines  1130 ,  1150  and passes within the electric element  100 , but does not leak toward the power source  90  through the transmission lines  1120 ,  1140 . In other words, the unwanted high-frequency current leaked from the CPU  110  flows within circuitry made up of the electric element  100 , transmission lines  1130 ,  1150 , capacitor  160 , transmission lines  1170 ,  1180  and the CPU  110 , without flowing through the transmission lines  1120 ,  1140  toward the power source  90 . 
     In this manner, the electric element  100  confines the unwanted high-frequency current produced by the CPU  110  within the vicinity of the CPU  110 . The capacitor  160  has a high capacity owing to the porous anode. This allows the capacitor  160  to quickly supply the DC current I to the CPU  110  in response to rapid start-up of the CPU  110 . 
     The present invention, as discussed above, realizes the rapid start-up of the CPU  110  by disposing the high-capacity capacitor  160  adjacent to the CPU  110 . 
       FIG. 35  is an another schematic view illustrating the structure of an electric circuit according to the sixth embodiment. Referring to  FIG. 35 , the electric circuit  1100 A includes an electric element  101 A having a capacitor  160  thereon, instead of the electric element  100  of the electric circuit  1100  shown in  FIG. 32 . The other components are the same as those of the electric circuit  1100 . 
       FIG. 36  is a cross-sectional view of the electric element  101 A and capacitor  160  shown in  FIG. 35 . Referring to  FIG. 36 , the electric element  101 A includes conductive plates  11 A,  12 A,  13 A,  21 A,  22 A instead of the conductive plates  11 ,  12 ,  21  to  23  of the electric element  100  (see  FIG. 4 ), and is added with a dielectric layer  6  and cathode electrodes  20 G,  20 H. The other components are the same as those of the electric element  100 . 
     Each of the conductive plates  11 A,  12 A,  13 A,  21 A,  22 A is composed of Ni and has a thickness in a range between 10 μm to 20 μm. Each of the conductive plates  11 A,  12 A,  13 A has the same dimensions as the conductive plates  11 ,  12 , while each of the conductive plates  21 A,  22 A has the same dimensions as the conductive plates  21  to  23 . The dielectric layer  6  is composed of BaTiO 3  and has the same dimensions as the dielectric layers  1  to  5 . 
     The conductive plate  11 A is placed so as to abut on the dielectric layers  1  and  2 , while the conductive plate  21 A is placed so as to abut on the dielectric layers  2  and  3 . The conductive plate  12 A is placed so as to abut on the dielectric layers  3  and  4 , while the conductive plate  22 A is placed so as to abut on the dielectric layers  4  and  5 . The conductive plate  13 A is placed so as to abut on the dielectric layers  5  and  6 , while the dielectric layer  6  is placed so as to abut on the conductive plate  13 A. 
     The side anode electrode  10 A is connected to one end of the conductive plates  11 A,  12 A,  13 A, while the side anode electrode  10 B is connected to the other end of the conductive plates  11 A,  12 A,  13 A. 
     Although it is not shown in  FIG. 36 , the side cathode electrodes  20 A,  20 B,  20 C,  20 D are connected to the conductive plates  21 A,  22 A. The cathode electrodes  20 G,  20 H are connected to the side cathode electrodes  20 A,  20 C, respectively. 
     In the capacitor  160 , a conductive polymeric layer  165 , dielectric oxide film  164 , tantalum sintered body  163 , dielectric oxide film  164  and conductive polymeric layer  165  are sequentially disposed in this order from the closer side to the conductive plate  13 A of the electric element  101 A. It is noted that the lead layer  166  of the capacitor  160  is omitted. Conductors  167 ,  168  are connected, through the lead layer  166 , with the conductive polymeric layer  165  which is a cathode. In the structure in which the capacitor  160  is mounted on the electric element  101 A, the conductors  167 ,  168  are disposed on cathode electrodes  20 G,  20 H, respectively, of the electric element  101 A. The cathode (i.e. conductive polymeric layer  165 ) of the capacitor  160  is thus connected to the cathode electrodes  20 E,  20 F of the electric element  101 A. Therefore, the conductors  167 ,  168  constitute the transmission line  1150  shown in  FIG. 35 . 
     In the electric element  101 A, a DC current I supplied from the power source  90  flows in the anode electrode  10 C, side anode electrode  10 A, conductive plates  11 A,  12 A,  13 A, side anode electrode  10 B and anode electrode  10 D in this order. In short, the DC current I flows through the conductive plates  11 A,  12 A,  13 A in the direction of arrow  105 . 
     Alternatively, a return current Ir supplied from the capacitor  160  flows in the cathode electrode  20 F, side cathode electrodes  20 C,  20 D, conductive plates  21 A,  22 A, side cathode electrodes  20 A,  20 B and cathode electrode  20 E in this order. In short, the return current Ir flows in the conductive plates  21 A,  22 A in the direction of arrow  106 . 
     In the capacitor  160 , the DC current I supplied from the electric element  101 A flows in the tantalum sintered body  163  (anode) in the direction of arrow  105 , while the return current Ir supplied from the CPU  110  flows in the conductive polymeric layer  165  (cathode) in the direction of arrow  106 . 
     For this configuration, the effective inductance of the conductive plates  11 A,  12 A becomes smaller than their self-inductance under the influence of the mutual inductance generated by the return current Ir passing within the electric element  101 A. The effective inductance of the conductive plate  13 A also becomes smaller than its self-inductance under the influence of the mutual inductance generated by the return current Ir flowing in the conductive plate  22 A of the electric element  101 A and the return current Ir flowing in the conductive polymeric layer  165  (cathode) of the capacitor  160 . As a result, the impedance of the electric element  101 A is lowered. 
     As discussed above, the effective inductance of the electric element  101 A decreases with the mutual inductance derived from the return current Ir flowing in the electric element  101 A and the mutual inductance derived from the return current Ir flowing in the capacitor  160 , and consequently the impedance is lowered. 
     Thus, the electric element  101 A can obtain the lower impedance than the electric element  100 . The electric element  101 A, therefore, can confine further the unwanted high-frequency current produced by the CPU  110  within the vicinity of the CPU  110 . In other words, the electric element  101 A can prevent still more leakage of the unwanted high-frequency current toward the power source  90 . 
     As discussed above, the electric circuit  1100 A is characterized in that the capacitor  160  is mounted on the electric element  101 A and the conductive plate  13 A (conductive plate where the DC current I flows) is placed at the closest position to the capacitor  160 . This characteristic feature enables the electric element  101 A, as discussed above, to make its impedance lower than that of the electric element  100 ; consequently, the unwanted high-frequency current produced by the CPU  110  can be further confined within the vicinity of the CPU. The placement of the capacitor  160  on the electric element  101 A can also reduce the area for mounting both on a board. 
     In the above embodiment, the conductive plate  13 A, in which the DC current I passes, of the electric element  101 A is arranged at the closest position to the capacitor  160 , because the capacitor  160  has the conductive polymeric layer  165 , in which the return current Ir flows, arranged at the closest position to the electric element  101 A. However, if the capacitor  160  has an electrode, in which the DC current I passes, placed at the closest position to the electric element  101 A, the conductive plate  22 A, in which the return current Ir flows, of the electric element  101 A should be disposed at the closest position to the capacitor  160 . 
     Of two direct currents flowing at the closest position in the electric element  101 A with respect to the capacitor  160  and flowing at the closest position in the capacitor  160  with respect to the electric element  101 A in the electric circuit  1100 A, either one should be the DC current I and the other should be the return current Ir. The conductive plate, to be placed closest to the capacitor  160 , in the electric element  101 A is thus determined to satisfy the above condition. Specifically, the conductive plate, to be placed at the closest position to the capacitor  160 , of the electric element  101 A passes a current in the opposite direction to a current flowing in the conductive plate, to be placed at the closest position to the electric element  101 A, of the capacitor  160 . 
     Although all the dielectric layers  1  to  6  are composed of the same dielectric material (BaTiO 3 ) in the above embodiment, the present invention is not limited to this. The dielectric layers  1  to  6  can be composed of different dielectric materials on an individual basis. Alternatively, the dielectric layers  1  to  6  can be put into two groups each composed of the same material, but the materials are different to each other. Typically the dielectric layers  1  to  6  may be composed of one or more kinds of dielectric materials. Any dielectric material for forming the dielectric layers  1  to  6  preferably has the relative permittivities of 3000 or more. 
     In addition to BaTiO 3 , the dielectric layers may be composed of Ba(Ti,Sn)O 3 , Bi 4 Ti 3 O 12 , (Ba, Sr, Ca)TiO 3 , (Ba, Ca)(Zr, Ti)O 3 , (Ba, Sr, Ca)(Zr, Ti)O 3 , SrTiO 3 , CaTiO 3 , PbTiO 3 , Pb(Zn, Nb)O 3 , Pb(Fe, W)O 3 , Pb(Fe, Nb)O 3 , Pb(Mg, Nb)O 3 , Pb(Ni, W)O 3 , Pb(Mg, W)O 3 , Pb(Zr, Ti)O 3 , Pb(Li, Fe, W)O 3 , Pb 5 Ge 3 O 11 , CaZrO 3 , or the like. 
       FIG. 37  is a perspective view illustrating an exemplary electric circuit according to the sixth embodiment.  FIG. 38  is a plan view of the electric circuit viewed from direction A of  FIG. 37 .  FIG. 39  is a plan view of the electric circuit viewed from direction B of  FIG. 37 .  FIG. 40  is a plan view of the electric circuit viewed from direction C of  FIG. 37 .  FIG. 41  is a cross-sectional view of the electric circuit taken along lines XXXXI-XXXXI of  FIG. 37 . 
     Referring to  FIGS. 37 and 38 , the electric circuit  1200  comprises an electric element  1210 , a capacitor  1220 , a copper plate  1230 , and resin  1240 . The electric element  1210  has the same structure as the electric element  101  shown in  FIG. 10 , and includes anode electrodes  1211 ,  1212  and cathode electrodes  1213 ,  1214 . The anode electrodes  1211 ,  1212  are connected to the copper plate  1230 . The electric element  1210  is mounted on the capacitor  1220 . 
     The capacitor  1220  has the same structure as the capacitor  160  shown in  FIG. 34  and includes an anode electrode  1221 . The anode electrode  1221  is connected to the copper plate  1230 . 
     The cathode electrodes  1213 ,  1214  of the electric element  1210  are disposed on the front face  1200 A, bottom face  1200 B, rear face  1200 C and top face  1200 D of the electric circuit  1200 . A cathode electrode (not shown) of the capacitor  1220  is connected to the cathode electrode  1214  of the electric element  1210 . 
     The resin  1240  seals around the capacitor  1220  and a part of the cathode electrode  1214 . The copper plate  1230  is shaped like a rectangle without one side in cross section and surrounds the electric element  1210 , capacitor  1220  and resin  1240 . 
     The copper plate  1230  has cut-away sections  1231 ,  1232 . The cathode electrodes  1213 ,  1214  are partially disposed on the top face of the electric element  1210  and within the area where the cut-away sections  1231 ,  1232  of the copper plate  1230  are located (see  FIG. 39 ). 
     The copper plate  1230  is arranged on opposite sides of the bottom face of the electric circuit  1200 . The cathode electrodes  1213 ,  1214  are placed on the inside of the copper plates arranged on the opposite sides (see  FIG. 40 ). 
     The cathode electrode  1214  is formed along the electric element  1210  but inwardly curved in an area in which the capacitor  1220  is placed. The curved parts of the cathode electrode  1214  make a connection with the cathode electrode of the capacitor  1220 . The resin  1240  fills interstices between the electric element  1210  and capacitor  1220 , under the capacitor  1220 , and the inside of the curved parts of the cathode electrode  1214  (see  FIG. 41 ). 
     The electric circuit  1200  is disposed between the power source  90  and CPU  110  and performs the same functions as the aforementioned electric circuit  1100 A. Such an electric circuit  1200  has an anode electrode  1211  and a cathode electrode  1213  connected to the power source  90 , and anode electrodes  1212 ,  1221  and a cathode electrode  1214  connected to the CPU  110 . 
     Thus, the electric circuit  1200  allows the capacitor  1220  to store a power source current supplied from the power source  90  and to supply the stored electrical current to the CPU  110 . The electric circuit  1200  concurrently prevents the unwanted high-frequency current produced by the CPU  110  from leaking toward the power source  90 . 
     The above-discussed electric circuit according to the sixth embodiment comprises the capacitor arranged between the power source and electric element and the electric element arranged between the capacitor and CPU and having low impedance. Because of this configuration, the electric circuit can store electric currents supplied from the power source and supply it to the CPU as confining the unwanted high-frequency current produced by the CPU within circuitry made up of the electric element and CPU. 
     Accordingly, the present invention can prevent the leakage of the unwanted high-frequency current toward the power source, and also rapidly start up an electrical load circuit. 
     The electric circuit  1100  according to the sixth embodiment can use any one of the electric elements  101 ,  200 ,  300 ,  400 ,  500 ,  600 ,  700  and  800  instead of the electric element  100 . 
     The electric circuit  1200  according to the sixth embodiment can use any one of the electric elements  100 ,  200 ,  300 ,  400 ,  500 ,  600 ,  700  and  800  instead of the electric element  101 . 
     The Seventh Embodiment 
       FIG. 42  is a schematic view of the structure of the electric circuit according to the seventh embodiment. Referring to  FIG. 42 , the electric circuit  1300  of the seventh embodiment comprises electric elements  1310 ,  1320 . Both electric elements  1310 ,  1320  have the same structure as the electric element  101  shown in  FIG. 10 . The electric element  1310  includes anode electrodes  1311 ,  1312  and cathode electrodes  1313 ,  1314 . The electric element  1320  includes anode electrodes  1321 ,  1322  and cathode electrodes  1323 ,  1324 . 
     In the electric element  1310 , overlap parts  20  of the conductive plates  11 ,  12  and conductive plates  21 ,  22  have length L 2  and width W 2  so set as to hold W 2 ≧L 2 . In the electric element  1320 , overlap parts  20  of the conductive plates  11 ,  12  and conductive plates  21 ,  22  have length L 2  and width W 2  so set as to hold L 2 &gt;W 2 . Thus, the electric element  1310  functions as a capacitor, on the other hand, the electric element  1320  functions as a noise filter. 
       FIG. 43  is a bottom view illustrating the electric elements  1310 ,  1320  shown in  FIG. 42 . Referring to  FIG. 43 , the anode electrodes  1311 ,  1312  are disposed on one side and the other side, respectively, both opposed to each other, of the electric element  1310  in the longitudinal direction, while the cathode electrodes  1313 ,  1314  are disposed on the inside of the anode electrodes  1311 ,  1312 . Specifically, the cathode electrode  1313  is disposed closer to the anode electrode  1311  than the midpoint between the anode electrodes  1311  and  1312 , while the cathode electrode  1314  is disposed closer to the anode electrode  1312  than the midpoint. 
     The anode electrodes  1321 ,  1322  are disposed on one side and the other side, respectively, both opposed to each other, of the electric element  1320  in the longitudinal direction, while the cathode electrodes  1323 ,  1324  are disposed on the inside of the anode electrodes  1321 ,  1322 . Specifically, the cathode electrode  1323  is disposed closer to the anode electrode  1321  than the midpoint between the two anode electrodes  1321 ,  1322 , while the cathode electrode  1324  is disposed closer to the anode electrode  1322  than the midpoint. 
       FIG. 44  is a plan view illustrating a board on which the electric circuit  1300  shown in  FIG. 42  is mounted. Referring to  FIG. 44 , the board  1330  has anode sections  1331  to  1333 , grounding sections  1334  to  1339 , cut-away sections  1340  to  1344 . The anode sections  1331  to  1333  and grounding sections  1334  to  1339  are formed by forming cut-away sections  1340  to  1344  in a conductor formed on the printed board. 
     The anode sections  1331 ,  1332 ,  1333  are formed in the cut-away sections  1340 ,  1342 ,  1344 , respectively. The grounding section  1336  is formed between the cut-away sections  1340  and  1341  and connected to the two grounding sections  1334 ,  1335 . The grounding section  1337  is formed between the cut-away sections  1341  and  1342  and connected to the two grounding sections  1334 ,  1335 . The grounding section  1338  is formed between the cut-away sections  1342  and  1343  and connected to the two grounding sections  1334 ,  1335 . The grounding section  1339  is formed between the cut-away sections  1343  and  1344  and connected to the two grounding sections  1334 ,  1335 . 
     Referring to  FIGS. 42 to 44 , the anode electrode  1311  of the electric element  1310  is placed on the anode section  1331 . The anode electrode  1312  is placed on the anode section  1332 . The cathode electrode  1313  is placed on the grounding sections  1334 ,  1336 ,  1335 . The cathode electrode  1314  is placed on the grounding sections  1334 ,  1337 ,  1335 . 
     The anode electrode  1321  of the electric element  1320  is placed on the anode section  1332 . The anode electrode  1322  is placed on the anode section  1333 . The cathode electrode  1323  is placed on the grounding sections  1334 ,  1338 ,  1335 . The cathode electrode  1324  is placed on the grounding sections  1334 ,  1339 ,  1335 . 
     This configuration allows the anode electrode  1312  of the electric element  1310  to be electrically connected to the anode electrode  1321  of the electric element  1320  through the anode section  1332 , while allowing the cathode electrodes  1313 ,  1314  of the electric element  1310  to be electrically connected to the cathode electrodes  1323 ,  1324  of the electric element  1320  through the grounding sections  1334 ,  1335 . 
     The electric circuit  1300  is used between the power source  90  and CPU  110  and connected to the power source  90  on the anode section  1331  side, and to the CPU  110  on the anode section  1333  side. Consequently, the electric element  1310  functioning as a capacitor is disposed near the power source  90 , while the electric element  1320  functioning as a noise filter is disposed near the CPU  110 . 
     Once the electric circuit  1300  is supplied with a power source current from the power source  90 , the power source current is stored in the electric element  1310  (i.e. capacitor) and then supplied to the CPU  110  through the electric element  1320  (i.e. noise filter). At the same time, the electric circuit  1300  confines the unwanted high-frequency current produced by the CPU  110  within circuitry made up of the CPU  110  and electric element  1320  (i.e. noise filter). 
     Accordingly, the present invention can prevent the leakage of the unwanted high-frequency current toward the power source and rapidly start up the electrical load circuit. 
     The electric circuit  1300  according to the seventh embodiment can use any one of electric elements  100 ,  200 ,  300 ,  400 ,  500 ,  600 ,  700  and  800  instead of the electric element  101 . 
       FIG. 45  is a schematic view illustrating the structure of the other electric circuit according to the seventh embodiment. The electric circuit according to the seventh embodiment can be replaced with this electric circuit  1400  shown in  FIG. 45 . Referring to  FIG. 45 , the electric circuit  1400  comprises electric elements  1410 ,  1420 ,  1430 . The electric element  1410  includes an anode electrode  1411  and a cathode electrode  1412 , each connected to one of conductive plates (not shown) which are opposed to each other. The two conductive plates of the electric element  1410  have length L 5  and width W 5  (&lt;L 5 ) each. The electric element  1410  has an approximately rectangular plane and functions as a noise filter. The board  1440  includes grounding sections  1441 ,  1443  and an anode section  1442 . 
       FIG. 46  is a plan view of the two electric elements  1420 ,  1430  shown in  FIG. 45 . Referring to  FIG. 46 , the electric element  1420  includes an anode electrode  1421  and a cathode electrode  1422 , each connected to one of conductive plates (not shown) which are opposed to each other. The two conductive plates of the electric element  1420  have length L 6  and width W 6  (L 6 ). The electric element  1430  includes an anode electrode  1431  and a cathode electrode  1432 , each connected to one of the conductive plates (not shown) which are opposed to each other. The two conductive plates of the electric element  1430  have approximately the same dimensions as the two conductive plates of the electric element  1420 . Accordingly, the electric elements  1420 ,  1430  have approximately rectangular planes and function as a capacitor. 
     In the case where the two electric elements  1420 ,  1430  are mounted on the board  1440 , the anode electrode  1421  of the electric element  1420  and the anode electrode  1431  of the electric element  1430  are arranged on the anode section  1442 , while the cathode electrode  1422  of the electric element  1420  and the cathode electrode  1432  of the electric element  1430  are arranged on the grounding section  1443 . Between the electric elements  1420  and  1430 , a space  1450  is formed. 
     The electric element  1410  is placed on the two electric elements  1420 ,  1430  which are mounted on the board  1440 . In this configuration, the anode electrode  1411  of the electric element  1410  is arranged on the anode electrode  1421  of the electric element  1420  and the anode electrode  1431  of the electric element  1430 , while the cathode electrode  1412  of the electric element  1410  is arranged on the cathode electrode  1422  of the electric element  1420  and the cathode electrode  1432  of the electric element  1430 . This configuration allows the anode electrode  1411  of the electric element  1410  to be connected to the anode electrode  1421  of the electric element  1420  and the anode electrode  1431  of the electric element  1430 , while allowing the cathode electrode  1412  of the electric element  1410  to be connected to the cathode electrode  1422  of the electric element  1420  and the cathode electrode  1432  of the electric element  1430 . 
       FIG. 47  is a side view of the electric circuit  1400  shown in  FIG. 45  viewed from direction A.  FIG. 48  is a bottom view of the electric circuit  1400  shown in  FIG. 45 . The electric element  1410  is mounted on the electric element  1430  and has the anode electrode  1411  connected to the anode electrode  1431  of the electric element  1430  and the cathode electrode  1412  connected to the cathode electrode  1432  of the electric element  1430  (see  FIG. 47 ). The two electric elements  1420 ,  1430  are disposed with space  1450  therebetween (see  FIG. 48 ). 
     The electric circuit  1400  is used between the power source  90  and CPU  110 . The anode electrodes  1421 ,  1431  and cathode electrodes  1422 ,  1432  of the electric elements  1420 ,  1430  are connected to the power source  90 , while the anode electrode  1411  and cathode electrode  1412  of the electric element  1410  are connected to the CPU  110 . 
     Once the electric circuit  1400  is supplied with a power source current from the power source  90 , the power source current is stored in the electric elements  1420 ,  1430  (i.e. capacitor) and supplied through the electric element  1410  (i.e. noise filter) to the CPU  110 . At the same time, the electric circuit  1400  confines the unwanted high-frequency current produced by the CPU  110  within circuitry made up of the CPU  110  and electric element  1410  (noise filter). 
     According to the present invention, the use of the electric element  1410  having two terminals and the electric elements  1420 ,  1430  each having two terminals can prevent the unwanted high-frequency current from leaking toward the power source and allows the electrical load circuit to rapidly start up. 
     The electric circuit  1400  can properly work without either of the electric element  1420  or  1403 . The provision of the two electric elements  1420 ,  1430  functioning as capacitors is for mounting the electric element  1410  with stability. The electric circuit capable of preventing the unwanted high-frequency current from leaking toward the power source and supplying the electric current to the electrical load circuit can be fully achieved with the electric element  1410  and any one of the electric elements  1420  and  1403 . 
     In the present invention, the conductive plates  11 ,  12  constitute “a first conductor”, while the conductive plates  21  to  23  constitute “a second conductor”. 
     The conductive wires  501  to  503  constitute “a first conductor”, while the conductive wires  511 ,  512  constitute “a second conductor”. 
     The conductive wires  601  to  603  constitute “a first conductor”, the conductive wires  611  to  613  constitute “a second conductor”. 
     The CPU  110  is “an electrical load circuit”. 
     The side face  100 A is “a first side face”, side face  100 B is “a second side face”, the front face  100 D is “a third side face”, and the rear face  100 E is “a fourth side face”. 
     In the present invention, the conductive plates  11 ,  12 ,  21  to  23 ,  201 ,  202 ,  301 ,  302 ,  311 ,  312 ,  401 ,  402 ,  411 ,  412  can be typically composed of metallic materials containing nickel as a main material. The dielectric layers  1  to  6  can be typically composed of ceramics containing BaTiO 3  as a main material. 
     In the present invention, the conductive plates  11 ,  12 ,  21  to  23 ,  201 ,  202 ,  301 ,  302 ,  311 ,  312 ,  401 ,  402 ,  411 ,  412  are equivalent to conductive layers. 
     It should be understood that the embodiments disclosed herein are to be taken as examples and are not limited. The scope of the present invention is defined not by the above described embodiments but by the following claims. All changes that fall within meets and bounds of the claims, or equivalence of such meets and bounds are intended to be embraced by the claims.