Patent ID: 8027145

Claim:
A capacitor element comprising: a porous plate dielectric substance made of an anodic oxide of a first valve metal, in which plural pores belonging to a first group and plural pores belonging to a second group, which pierce through in the thickness direction, are formed, wherein single pores belonging to the first group and single pores belonging to the second group are arranged alternately in a direction perpendicular to the thickness direction, each pore being a nano-sized pore having a diameter of several nm to several hundred nm; first pillar-shaped electrodes formed in the plural pores belonging to the first group respectively wherein base ends thereof are exposed at one principal surface of the dielectric substance; second pillar-shaped electrodes formed in the plural pores belonging to the second group respectively wherein base ends thereof are exposed at another principal surface of the dielectric substance; insulator layers provided respectively on tips of the first pillar-shaped electrodes in the pores belonging to the first group so as to fill the pores as well as on tips of the second pillar-shaped electrodes in the pores belonging to the second group so as to fill the pores; a first hide electrode provided on the one principal surface of the dielectric substance so as to connect to the base ends of the first pillar-shaped electrodes; and a second hide electrode provided on the another principal surface of the dielectric substance so as to connect to the base ends of the second pillar-shaped electrodes.