Patent Publication Number: US-11031228-B2

Title: Mass spectrometry device and mass spectrometry method

Description:
TECHNICAL FIELD 
     An aspect of the present invention relates to a mass spectrometry device and a mass spectrometry method. 
     BACKGROUND ART 
     As a technique for ionizing a sample such as a biological sample in order to perform mass spectrometry or the like, matrix-assisted laser desorption/ionization (MALDI) is known thus far. MALDI is a technique for ionizing a sample by mixing the sample with a low-molecular weight organic compound, called a matrix, absorbing an ultraviolet laser beam, and applying the laser beam to the mixture. According to this technique, a heat-labile substance or a high-molecular-weight substance can be subjected to non-destructive ionization (so-called soft ionization). However, MALDI generates background noise derived from the matrix. 
     As a technique for performing ionization without using such a matrix, surface-assisted laser desorption/ionization (SALDI) for ionizing a sample by using a substrate whose surface has an uneven microstructure is known. For example, as an ionization method of a sample according to SALDI, there is a method of using a surface having anodized porous alumina, anodized porous silicon, or the like having fine concavities as a sample holding surface (see Patent Literatures 1 and 2 below). In this ionization method, a sample to be analyzed is dropped onto the sample holding surface having the fine concavities, and a laser beam is applied after drying the sample to ionize the sample. 
     CITATION LIST 
     Patent Literature 
     
         
         [Patent Literature 1] Japanese Patent No. 5129628 
         [Patent Literature 2] U.S. Pat. No. 6,288,390 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, in the above ionization method, since a positional deviation of the sample with respect to the substrate occurs when the sample is dropped, it is difficult to ionize the sample while maintaining original positional information of the sample (a two-dimensional distribution of molecules composing the sample). For this reason, it is difficult to measure what kind of and how many molecules are present at each position of a sample region and use the ionization method in imaging mass spectrometry or the like imaging a two-dimensional distribution map of the sample molecules. Even when a method of transferring the sample to the substrate instead of dropping the sample onto the substrate is adopted, there is a problem in that a positional deviation of the sample with respect to the substrate occurs when the sample is transferred or an uneven transfer of the sample occurs. 
     Therefore, an aspect of the present invention is directed to providing a mass spectrometry device and a mass spectrometry method capable of ionizing a sample while maintaining positional information of the sample. 
     Solution to Problem 
     A mass spectrometry device according to an aspect of the present invention includes: a sample stage on which a sample is placed and on which a sample support having a substrate, in which a plurality of through-holes passing from one surface thereof to the other surface thereof are provided, and a conductive layer, which is formed of a conductive material and covers at least a portion of the one surface which is not provided with the through-holes, is placed such that the other surface faces the sample; a laser beam application unit configured to control application of a laser beam such that the laser beam is applied to an imaging target region on the one surface; and a detection unit configured to detect the sample ionized by the application of the laser beam in a state where a positional relation of the sample in the imaging target region is maintained. 
     According to the mass spectrometry device, the ionization of the sample can be performed by a simple operation of disposing the sample support on the sample while maintaining positional information of the sample. The laser beam application unit applies the laser beam to the imaging target region on the one surface, and the detection unit detects the ionized sample in the state where the positional relation of the sample in the imaging target region is maintained, so that a two-dimensional distribution of sample molecules can be seen. Further, an image resolution in imaging mass spectrometry depends on diameters of the through-holes of the sample support. Therefore, according to the mass spectrometry device, a high image resolution can be obtained in the imaging mass spectrometry of imaging a two-dimensional distribution map of the sample molecules. 
     A mass spectrometry device according to another aspect of the present invention includes: a sample stage on which a sample is placed and on which a sample support having a substrate, which is formed of a conductive material and in which a plurality of through-holes passing from one surface thereof to the other surface thereof are provided, is placed such that the other surface faces the sample; a laser beam application unit configured to control application of a laser beam such that the laser beam is applied to an imaging target region on the one surface; and a detection unit configured to detect the sample ionized by the application of the laser beam in a state where a positional relation of the sample in the imaging target region is maintained. 
     According to the mass spectrometry device, as the substrate formed of a conductive material is used, the conductive layer can be omitted, and the same effect as in the case where the sample support having the aforementioned conductive layer is used can be obtained. 
     In the mass spectrometry devices according to the aspect and the other aspect described above, the laser beam application unit may control the application of the laser beam using a portion or all of an effective region of the sample support, which functions as a region for moving the sample from the other surface to the one surface due to a capillary phenomenon, as the imaging target region. According to this configuration, the imaging mass spectrometry can be appropriately performed in the effective region. Further, the mass spectrometry devices according to the aspect and the other aspect described above may further include an image formation optical system configured to form an image of the ionized sample on the detection unit in the state where the positional relation of the sample in the imaging target region is maintained. Further, the image formation optical system may be an electrostatic lens. 
     A mass spectrometry method according to an aspect of the present invention includes: a first step of preparing a sample support having a substrate in which a plurality of through-holes passing from one surface thereof to the other surface thereof are provided and a conductive layer that is formed of a conductive material and covers at least the one surface; a second step of placing a sample on a sample stage and arranging the sample support on the sample such that the other surface faces the sample; a third step of applying a laser beam to an imaging target region on the one surface and ionizing a sample moved from the other surface side to the one surface side via the through-holes due to a capillary phenomenon; and a fourth step of detecting the sample ionized in the third step in a state where a positional relation of the sample in the imaging target region is maintained. 
     According to the mass spectrometry method, the ionization of the sample can be performed by a simple operation of disposing the sample support on the sample while maintaining positional information of the sample. A two-dimensional distribution of sample molecules can be seen by applying the laser beam to the imaging target region on the one surface and detecting the ionized sample in the state where the positional relation of the sample in the imaging target region is maintained. Further, an image resolution in imaging mass spectrometry depends on diameters of the through-holes of the sample support. Therefore, according to the mass spectrometry method, a high image resolution can be obtained in the imaging mass spectrometry of imaging a two-dimensional distribution map of the sample molecules. 
     A mass spectrometry method according to another aspect of the present invention includes: a first step of preparing a sample support having a substrate which is formed of a conductive material and in which a plurality of through-holes passing from one surface thereof to the other surface thereof are provided; a second step of placing a sample on a sample stage and arranging the sample support on the sample such that the other surface faces the sample; a third step of applying a laser beam to an imaging target region on the one surface and ionizing the sample moved from the other surface side to the one surface side via the through-holes due to a capillary phenomenon; and a fourth step of detecting the sample ionized in the third step in a state where a positional relation of the sample in the imaging target region is maintained. 
     According to the mass spectrometry device, as the substrate formed of a conductive material is used, the conductive layer can be omitted, and the same effect as in the case where the sample support having the aforementioned conductive layer is used can be obtained. 
     In the mass spectrometry methods according to the aspect and the other aspect described above, the laser beam may be applied in the third step using a portion or all of an effective region of the sample support, which functions as a region for moving the sample from the other surface to the one surface due to a capillary phenomenon, as the imaging target region. According to this configuration, the imaging mass spectrometry can be appropriately performed in the effective region. Further, an image formation optical system may form an image of the ionized sample on the detection unit in the fourth step in the state where the positional relation of the sample in the imaging target region is maintained. Further, the image formation optical system may be an electrostatic lens. 
     Advantageous Effects of Invention 
     According to an aspect of the present invention, a mass spectrometry device and a mass spectrometry method capable of ionizing a sample while maintaining positional information of the sample can be provided. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating an outline of a mass spectrometry method according to an embodiment. 
         FIG. 2  is a perspective view of a sample support used in the mass spectrometry method according to the present embodiment. 
         FIG. 3  is a sectional view taken along line III-III of  FIG. 2 . 
         FIG. 4  is an enlarged plan view of an effective region R of the sample support of  FIG. 2 . 
         FIG. 5  is an enlarged sectional view of major parts of the sample support of  FIG. 2 . 
         FIG. 6  is view illustrating a step of manufacturing a substrate of  FIG. 2 . 
         FIG. 7  is a view illustrating a procedure of the mass spectrometry method according to the present embodiment. 
         FIG. 8  is a view illustrating a procedure of the mass spectrometry method according to the present embodiment. 
         FIG. 9  is a view illustrating a procedure of the mass spectrometry method according to the present embodiment. 
         FIG. 10  is a view illustrating an outline of a mass spectrometry method according to a modification. 
         FIG. 11  is a view illustrating a relation between a hole width of a through-hole and a mass spectrum. 
         FIG. 12  is a view illustrating a relation between the hole width of the through-hole and the mass spectrum. 
         FIG. 13  is a view illustrating a relation between the hole width of the through-hole and the mass spectrum. 
         FIG. 14  is a view illustrating a relation between the hole width of the through-hole and the mass spectrum. 
         FIG. 15  is a view illustrating a relation between a thickness of a substrate and signal intensity. 
         FIG. 16  is a view illustrating a first modification of the sample support. 
         FIG. 17  is a view illustrating a second modification of the sample support. 
         FIG. 18  is a view illustrating a third modification of the sample support. 
         FIG. 19  is a view illustrating a mass spectrum according to mass spectrometry using a sample support before being baked and a mass spectrum according to mass spectrometry using a sample support after being baked. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the same or equivalent portions are denoted by the same reference signs in each of the drawings, and duplicate descriptions thereof will be omitted. Dimensions of members (or portions) illustrated in the drawings or ratios of the dimensions may be different from actual dimensions or ratios of the actual dimensions in order to facilitate understanding of the description. 
     An outline of a mass spectrometry method (including a surface-assisted laser desorption/ionization (SALDI) method) according to the present embodiment will be described using  FIG. 1 . As illustrated in (a) of  FIG. 1 , in the mass spectrometry method, first, one sample  10  to be subjected to mass spectrometry is placed on a sample stage  1 . Further, a sample support  2  having a substrate in which a plurality of through-holes are provided is arranged on the sample  10 . Here, the sample  10  to be subjected to spectrometry is a thin film-like biological sample (a hydrous sample) such as a tissue section. 
     Subsequently, as illustrated in (b) of  FIG. 1 , the sample  10  is moved from a lower surface side of the sample support  2  to an upper surface side of the sample support  2  via the through-holes by a capillary phenomenon. The sample  10  stays on the upper surface side of the sample support  2  due to surface tension. 
     Subsequently, as illustrated in (c) of  FIG. 1 , an ultraviolet laser beam is applied to the upper surface side of the sample support  2 , and thereby the sample  10  moved to the upper surface side of the sample support  2  is ionized and emitted into a vacuum. To be specific, energy of the ultraviolet laser beam is transmitted from the sample support  2  absorbing the energy to the sample  10  moved to the upper surface side of the sample support  2 . The sample  10  obtaining the energy is evaporated and obtains electric charges to be sample ions (an ionized sample)  11 . The sample ions  11  emitted into the air in this way are detected by a detector  3 , and the detected sample ions  11  are measured. In this way, mass spectrometry of the sample  10  is performed. 
     The mass spectrometry method according to the present embodiment uses time-of-flight mass spectrometry (TOF-MS) by way of example. An outline of TOF-MS is shown below. In TOF-MS, a ground electrode (not shown) is provided between the sample support  2  and the detector  3 , and a predetermined voltage is applied to the sample support  2 . Thereby, a potential difference occurs between the sample support  2  and the ground electrode, and the sample ions  11  generated at the upper surface side of the sample support  2  are accelerated and moved toward the ground electrode by the potential difference. Afterward, the sample ions  11  fly in a drift space in which there are no electric or magnetic fields provided from the ground electrode to the detector  3 , and finally arrive at the detector  3 . Here, since the potential difference between the sample support  2  and the ground electrode is constant with respect to any of the sample ions  11 , energy given to each of the sample ions  11  is constant. For this reason, the sample ions  11  having a smaller molecular weight fly in the drift space at a higher speed and arrive at the detector  3  within a shorter time. In TOF-MS, mass spectrometry is performed on the basis of a difference between arrival times of the sample ions  11  at the detector  3 . 
     Next, the sample support  2  will be described using  FIGS. 2 to 5 .  FIG. 2  is a perspective view illustrating an external appearance of the sample support  2  (a substrate  21  and a frame  22 ). In practice, a plurality of through-holes S are provided in the substrate  21 , and the sample support  2  is provided with a bonding layer G that bonds the substrate  21  and the frame  22 , and a conductive layer  23  that covers surfaces of the substrate  21  and the frame  22  (including inner surfaces of the through-holes  5 ). However, since these layers are extremely small with respect to the substrate  21  and the frame  22 , these layers are not illustrated in  FIG. 2 . Meanwhile, in  FIG. 3 , which is a sectional view taken along line of  FIG. 2 , the through-holes S, the conductive layer  23 , and the bonding layer G are shown in dimensions larger than actual dimensions in order to describe arrangement configurations of the through-holes S, the conductive layer  23 , and the bonding layer G 
     As illustrated in  FIGS. 2 and 3 , the sample support  2  is a sample support for the SALDI method and has the rectangular plate-like substrate  21  in which the plurality of through-holes S are provided to pass from one surface  21   a  thereof to the other surface  21   b  thereof, and the frame  22  that is mounted on an outer edge of the one surface  21   a  of the substrate  21 . 
     The one surface  21   a  and the other surface  21   b  of the substrate  21  have, for instance, square shapes in which a length D 1  of one side thereof is 1 cm. A thickness d 1  from the one surface  21   a  to the other surface  21   b  of the substrate  21  is 1 to 50 μm. In the present embodiment, the substrate  21  is formed of an insulating material by way of example. The substrate  21  is, for instance, an alumina porous film in which the plurality of through-holes S, each of which has a nearly constant hole diameter, are formed by anodizing aluminum (Al). The substrate  21  may be formed by anodizing a valve metal other than Al such as tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), zinc (Zn), tungsten (W), bismuth (Bi), antimony (Sb), or the like, or by anodizing silicon (Si). 
     The frame  22  is provided along the outer edge of the one surface  21   a  of the substrate  21  in a quadrilateral ring shape. A width D 2  of the frame  22  is, for instance, 2 mm. A thickness d 2  of the frame  22  is, for instance, 10 to 500 μm. An effective region R of the one surface  21   a  of the substrate  21  which is not covered with the frame  22  is a square region of 0.6 mm squared. The effective region R functions as a region for moving the sample  10  from the other surface  21   b  to the one surface  21   a  due to a capillary phenomenon (to be described below). Because the frame  22  is provided at an outer edge of the substrate  21 , bending of the substrate  21  is suppressed. Since a portion at which the frame  22  is provided can be fixed or grasped, handling thereof is facilitated when the sample support  2  is supported or moved. In the present embodiment, the frame  22  is provided in the quadrilateral ring shape, but it may be provided along the outer edge of the substrate  21  in an annular shape. Because the frame  22  is provided in the annular shape, the bending of the substrate  21  is suppressed more than in a case where the frame  22  is provided in the quadrilateral ring shape. 
     As illustrated in  FIG. 3 , the frame  22  is bonded to a surface (the one surface  21   a ) of the substrate  21  via the bonding layer G As a material of the bonding layer G, a bonding material emitting a small amount of gas, such as low-melting-point glass, or an adhesive for a vacuum can be used. In the present embodiment, the frame  22  is bonded to the substrate  21  by overlapping a portion in which the through-holes S are provided in the one surface  21   a  of the substrate  21  by way of example. For this reason, the through-holes S allow bending of interfaces between the portion at which the frame  22  is provided and a portion at which the frame  22  is not provided in the substrate  21 . Thereby, the substrate  21  is inhibited from being broken on the boundary surface. 
     The frame  22  has nearly the same coefficient of thermal expansion as the substrate  21 . The frame  22  is, for instance, a ceramic member or the like having the same composition as the substrate  21 . The frame  22  is formed of, for instance, glass or a metal. In this way, the coefficients of thermal expansion of the substrate  21  and the frame  22  approximate each other, and thereby deformation or the like (for instance, strains of the substrate  21  and the frame  22  during thermal expansion) caused by a change in temperature can be prevented. 
     As illustrated in  FIGS. 3 and 5 , the sample support  2  has the conductive layer  23  that covers the one surface  21   a  and the other surface  21   b  of the substrate  21 , the inner surfaces of the through-holes  5 , and a surface of the frame  22 . The conductive layer  23  is a layer formed of a conductive material provided to give conductivity to the insulating substrate  21 . However, the conductive layer  23  is not hindered from being provided even when the substrate  21  is formed of a conductive material. As the material of the conductive layer  23 , a metal having a low affinity (reactivity) with the sample  10  and high conductivity is preferred due to reasons that will be mentioned below. 
     For example, when the conductive layer  23  is formed of a metal such as copper (Cu) having a high affinity with the sample  10  such as a protein, the sample  10  may be ionized with Cu atoms attached to sample molecules in a step (to be described below) of ionizing the sample  10 . That is, when a molecular weight of the sample ions  11  detected by the detector  3  is measured, the measured weight deviates from an actual molecular weight of the sample  10  by a mass of the attached Cu, and hence accurate measurement is not performed. Therefore, as the material of the conductive layer  23 , a metal having a low affinity with the sample  10  is preferred. 
     Meanwhile, a metal having high conductivity can give a constant voltage in an easy and stable way. For this reason, when a metal having high conductivity is used as the conductive layer  23 , a constant voltage is easily applied to the substrate  21  in order to generate a constant potential difference between the aforementioned ground electrode and the substrate  21 . In addition, since a metal having higher conductivity shows a tendency to have higher thermal conductivity, the energy of the laser beam applied to the substrate  21  can be efficiently transmitted to the sample  10  via the conductive layer  23 . Therefore, as the material of the conductive layer  23 , a metal having high conductivity is preferred. 
     From the above viewpoint, for example, gold (Au), platinum (Pt), or the like is used as the material of the conductive layer  23 . For example, the conductive layer  23  can be formed by forming a film of Au or Pt on the one surface  21   a  and the other surface  21   b  of the substrate  21 , the inner surfaces of the through-holes S, and the surface of the frame  22  using a plating method, an atomic layer deposition (ALD) method, a vapor deposition method, a sputtering method, or the like. In addition to Au and Pt, for example, chromium (Cr), nickel (Ni), titanium (Ti), etc. can be used as the material of the conductive layer  23 . 
       FIG. 4  is an enlarged plan view of the effective region R of the sample support  2 . In  FIG. 4 , black portions denote the through-holes S, and white portions denote partition wall portions at which the through-holes S are not formed. As illustrated in  FIG. 4 , the plurality of through-holes S having approximately constant sizes are formed on the surface of the substrate  21 . The plurality of through-holes S may be formed at such a size that the sample  10  can be moved (raised) from the other surface  21   b  to the one surface  21   a  by a capillary phenomenon (to be described below). As in the example of  FIG. 4 , the sizes of the through-holes S may be uneven, and portions at which the plurality of through-holes S are coupled to one another may be present. An aperture ratio of the through-holes S (an area of portions at which the through-holes S are formed/a whole area) in the effective region R ranges from 10% to 80% from a practical point of view, and particularly preferably ranges from 60% to 80%. 
     As illustrated in  FIG. 5 , the through-holes S extend from the one surface  21   a  side to the other surface  21   b  side of the substrate  21 . A width d 3  of each of the through-holes S is 1 to 700 nm. A thickness d 4  of the conductive layer  23  is, for instance, about 1 to 25 nm. Here, the width d 3  of each of the through-holes S is a hole width after the conductive layer  23  is formed in the through-holes S. When the substrate  21  having the through-holes S, each of which has a hole width of 1 to 700 nm, is used, the movement of the sample  10  caused by the aforementioned capillary phenomenon can be more smoothly performed. As in the present embodiment, when a sectional shape of each of the through-holes S is a nearly circular shape, the width d 3  of each of the through-holes S refers to a diameter of each hole. Meanwhile, when the sectional shape of each of the through-holes S is not a circular shape, the width of each of the through-holes S refers to a diameter (an effective diameter) of an imaginary cylinder fitted into each of the through-holes S. 
     Next, a step of manufacturing the sample support  2  will be described using  FIGS. 3 and 6 . First, a step of manufacturing the substrate  21  will be described using  FIG. 6 . As illustrated in (a) of  FIG. 6 , an Al substrate  50  that will become a material of the substrate  21  is prepared. Subsequently, as illustrated in (b) of  FIG. 6 , the Al substrate  50  is anodized. Thereby, the Al substrate  50  is oxidized from a surface thereof, and an anodized film  51  having a plurality of concavities  51   a  is Ruined. Subsequently, as illustrated in (c) of  FIG. 6 , the anodized film  51  is peeled from the Al substrate  50 , and a bottom  51   b  of the anodized film  51  is removed or perforated. Thereby, the substrate  21  in which the plurality of through-holes S passing from one surface  21   a  to the other surface  21   b  thereof are provided is obtained. 
     After the substrate  21  is manufactured in this way, the frame  22  is mounted on an outer edge of the substrate  21  via the bonding layer G such as low-melting-point glass or an adhesive for a vacuum. Thereby, the state before the conductive layer  23  is formed in the sample support  2  illustrated in  FIG. 3  is obtained. Finally, the conductive layer  23  formed of Au or Pt is provided to cover the one surface  21   a  and the other surface  21   b  of the substrate  21 , the inner surfaces of the through-holes S, and the surface of the frame  22 . As described above, the conductive layer  23  is formed by forming a film of Au or Pt on the one surface  21   a  and the other surface  21   b  of the substrate  21 , the inner surfaces of the through-holes S, and the surface of the frame  22  using a plating method, an ALD method, or the like. Thereby, the sample support  2  illustrated in  FIG. 3  is manufactured. 
     In the anodization of Al, the substrate  21  is adjusted to have the thickness d 1  of 1 to 50 μm, and each of the through-holes S is adjusted to have the width d 3  of 1 to 700 nm. To be specific, conditions such as a thickness of the Al substrate  50  prepared first or a temperature, a voltage, etc. in the anodization of the Al substrate  50  are properly set, and thereby the thickness d 1  of the substrate  21  and the width d 3  of each of the through-holes S are formed to have predetermined sizes (sizes included in the above ranges). 
     Next, a procedure of the mass spectrometry method using the sample support  2  will be described using  FIGS. 7 to 9 . In  FIGS. 7 to 9 , the conductive layer  23 , the through-holes S, and the bonding layer G are not illustrated. 
     First, a mass spectrometry device  100  for performing mass spectrometry using the sample support  2  will be described using  FIG. 9 . The mass spectrometry device  100  comprises the sample stage  1  on which the sample  10  is placed, a laser beam application unit  4 , and the detector (the detection unit)  3 . 
     In a state where the sample support  2  is arranged on the sample  10  placed on the sample stage  1 , the laser beam application unit  4  applies a laser beam L to the one surface  21   a  while changing application positions thereof. Here, the sample support  2  is placed on the sample  10  such that the other surface  21   b  comes into contact with the sample  10  via the conductive layer  23 . The laser beam L applied by the laser beam application unit  4  is, for instance, an ultraviolet laser beam such as a nitrogen laser beam (an N 2  laser beam) having a wavelength of 337 nm or the like. 
     The detector  3  detects the sample  10  (the sample ions  11 ), which is ionized by applying the laser beam L from the laser beam application unit  4  at each application position. To be specific, the laser beam application unit  4  performs two-dimensional scanning on the effective region R of the sample support  2  according to a predetermined movement width and a predetermined moving direction, and applies the laser beam L at each scanning position. The detector  3  detects the sample ions  11  generated by the laser beam L being applied at each scanning position. Thereby, mass spectrometry can be performed at each position on the effective region R. Results of the mass spectrometry at each position of the sample  10  obtained in this way are synthesized, and thereby imaging mass spectrometry for imaging a two-dimensional distribution map of sample molecules can be performed. A procedure of the mass spectrometry performed by the mass spectrometry device  100  will be described below in detail using  FIGS. 7 to 9 . 
     First, the aforementioned sample support  2  is prepared (a first step). The sample support  2  may be prepared by a person who performs the mass spectrometry and manufactures the sample support  2  in person using the mass spectrometry device  100 , or by acquiring the sample support  2  from a manufacturer, a seller, or the like of the sample support  2 . 
     Subsequently, as illustrated in (a) of  FIG. 7 , the sample  10  to be subjected to mass spectrometry is placed on a placement surface  1   a  of the sample stage  1  and, as illustrated in (b) of  FIG. 7 , the sample support  2  is arranged on the sample  10  such that the other surface  21   b  comes into contact with the sample  10  via the conductive layer  23  (see  FIG. 3 ) (a second step). Here, to move the sample  10  targeted on the spectrometry to the one surface  21   a  side of the substrate  21  according to a capillary phenomenon, the sample support  2  is arranged on the sample  10  such that the sample  10  is included within the effective region R in the planar view. To smooth the movement of the sample  10  caused by the capillary phenomenon (to be described below), a solution (for instance, an acetonitrile mixture or the like) for reducing viscosity of the sample  10  may be mixed with the sample  10 . 
     Subsequently, as illustrated in (c) of  FIG. 8 , the sample support  2  is fixed to the sample stage  1  (a continuation of the second step). Here, as an example, four sides of the sample support  2  (upper and lateral surfaces of the frame  22  and lateral surfaces of the substrate  21 ) are fixed to the placement surface  1   a  of the sample stage  1  by an adhesive tape T having conductivity such as a carbon tape or the like. In this way, as the sample support  2  is fixed to the sample stage  1 , the sample  10  and the sample support  2  are brought into close contact with each other, and the movement of the sample  10  caused by the capillary phenomenon (to be described below) can be more smoothly performed. Sideslip of the sample support  2  arranged on the sample  10  can be prevented, and a loss of positional information of the sample  10  due to the sideslip of the sample support  2  can be suppressed. 
     Here, when the sample stage  1  has conductivity, the sample stage  1  and the sample support  2  are electrically connected by the adhesive tape T having conductivity. Therefore, a predetermined current is applied to the sample stage  1  in the state where the sample support  2  is fixed to the sample stage  1  by the adhesive tape T as illustrated in (c) of  FIG. 8 , and thereby a predetermined voltage is applied to the substrate  21 . Thereby, a constant potential difference can be generated between the aforementioned ground electrode and the substrate  21 . In the present embodiment, since the conductive layer  23  covers the frame  22  and the adhesive tape T is in contact with the conductive layer  23  on the frame  22 , the sample support  2  and a power source (a predetermined power source that applies the current to the sample stage  1 ) can be brought into contact with each other on the frame  22 . That is, the sample support  2  and the power source can be brought into contact with each other without reducing the effective region R on the substrate  21 . 
     As illustrated in (d) of  FIG. 8 , as described above, the sample support  2  is arranged on the sample  10 , and thereby the sample  10  is moved (raised) from the other surface  21   b  side of the substrate  21  toward the one surface  21   a  side via the through-holes S by the capillary phenomenon. The sample  10  enters a state where it stays on the one surface  21   a  side of the sample support  2  due to surface tension. Here, the placement surface  1   a  of the sample stage  1  and the one surface  21   a  and the other surface  21   b  of the substrate  21  are arranged to be nearly parallel to each other. Therefore, the sample  10  placed on the sample stage  1  is moved from the other surface  21   b  side to the one surface  21   a  side of the substrate  21  via the through-holes S in a direction perpendicular to the placement surface  1   a  of the sample stage  1  due to the capillary phenomenon. Thereby, before and after the movement caused by the capillary phenomenon, the positional information of the sample  10  (each sample molecule composing the sample  10 ) is maintained. In other words, two-dimensional coordinates (positions on a two-dimensional plane parallel to the placement surface  1   a  of the sample stage  1 ) of each sample molecule composing the sample  10  are not greatly changed before and after the movement caused by the capillary phenomenon. Accordingly, due to this capillary phenomenon, the sample  10  can be moved from the other surface  21   b  side to the one surface  21   a  side of the substrate  21  while the positional information of the sample  10  is maintained. 
     Subsequently, as illustrated in  FIG. 9 , the laser beam L is applied to the one surface  21   a  of the substrate  21  by the laser beam application unit  4 , and the sample  10  moved from the other surface  21   b  side to the one surface  21   a  side via the through-holes S by the capillary phenomenon is ionized (a third step). The ionized sample  10  (the sample ions  11 ) is detected by the detector  3  (a fourth step). While changing application positions of the laser beam L, the application of the laser beam L in the third step and the detection of the sample ions  11  in the fourth step are performed at each application position. To be specific, the laser beam application unit  4  scans the effective region R according to a predetermined movement width and a predetermined moving direction, and applies the laser beam L at each application position while changing the application positions of the laser beam L. The detector  3  detects the sample ions  11  emitted into a vacuum by applying the laser beam L from the laser beam application unit  4  at each application position. As a result, imaging mass spectrometry for imaging a two-dimensional distribution map of sample molecules can be performed on the basis of measurement results of the sample ions  11  detected at each application position. 
     According to the SALDI method (the first to third steps), the substrate  21  in which the plurality of through-holes S are provided is arranged on the sample  10 , and thereby the sample  10  can be raised from the other surface  21   b  side toward the one surface  21   a  side of the substrate  21  via the through-holes S due to a capillary phenomenon. Thereby, the sample  10  can be moved from the other surface  21   b  side to the one surface  21   a  side of the substrate  21  while the positional information of the sample  10  (the two-dimensional distribution of the molecules composing the sample  10 ) is maintained. The laser beam L is applied to the one surface  21   a  of the substrate  21 , and energy is transmitted to the sample  10  moved to the one surface  21   a  side via the conductive layer  23 . Thereby, the sample  10  is ionized. As a result, the sample  10  can be ionized while the positional information of the sample  10  is maintained. Therefore, according to the aforementioned method, the sample  10  can be ionized by a simple operation in which the substrate  21 , in which the plurality of through-holes S are provided, is placed on the sample  10  while the positional information of the sample  10  is maintained. 
     Al is anodized, and thereby the sample support  2  having the substrate  21  in which the plurality of through-holes S are provided is used. Thereby, the movement of the sample  10  caused by the aforementioned capillary phenomenon can be properly realized. Here, even when the sample support  2  having the substrate  21  obtained by anodizing a valve metal other than Al or Si instead of Al is used, the same effects are obtained. 
     The substrate  21  having the through-holes S, each of which has the hole width d 3  of 1 to 700 nm, is used, and thereby the movement of the sample  10  caused by the aforementioned capillary phenomenon can be more smoothly performed. 
     Since the sample support  2  has the frame  22  mounted on the outer edge of the one surface  21   a  of the substrate  21 , the bending of the substrate  21  is suppressed by the frame  22 , and the sample support  2  is easily handled when supported or moved. For this reason, the arrangement of the sample support  2  on the sample  10  in the second step can be easily performed. 
     According to the mass spectrometry method (the first to fourth steps), the sample  10  can be ionized by a simple operation in which the sample support  2  is arranged on the sample  10  while the positional information of the sample  10  is maintained. While changing the application positions of the laser beam L, the ionized sample  10  (the sample ions  11 ) is detected at each application position, and thereby the two-dimensional distribution of the sample molecules can be perceived. Therefore, according to the mass spectrometry method, the imaging mass spectrometry for imaging the two-dimensional distribution map of the sample molecules can be performed by the simple operation. 
     According to the mass spectrometry device  100 , the sample  10  can be ionized by a simple operation in which the sample support  2  is arranged on the sample  10  while the positional information of the sample  10  is maintained. The laser beam application unit  4  applies the laser beam L while changing the application positions, and the detector  3  detects the ionized sample  10  (the sample ions  11 ) at each application position, and thereby the two-dimensional distribution of the sample molecules can be perceived. Therefore, according to the mass spectrometry device  100 , imaging mass spectrometry for imaging a two-dimensional distribution map of sample molecules can be performed by the simple operation. 
     The use of the mass spectrometry device  100  is not limited to the imaging mass spectrometry. For example, the mass spectrometry device  100  may acquire signal intensity for each mass-to-charge ratio by applying the laser beam L only to a portion of the effective region R and detecting the sample  10  (the sample ions  11 ) ionized by the laser beam L. The mass spectrometry of the sample  10  can also be performed by this mass spectrometry method. Further, a signal free from the noise derived from the matrix in the conventional MALDI can also be obtained by this mass spectrometry method. In a case where the ionization of the sample  10  caused by the application of the laser beam L to a portion of the effective region R is insufficient, the mass spectrometry device  100  may continue to apply the laser beam L to the other portions of the effective region R. That is, the mass spectrometry device  100  may change the application positions of the laser beam L inside the effective region R until the ionization of the sample  10  becomes sufficient and the signal intensity for each mass-to-charge ratio can be appropriately acquired. 
     Further, the mass spectrometry device  100  is of a so-called scanning type, but a mass spectrometry device  200  of a so-called projection type may be used as the mass spectrometry device that performs the imaging mass spectrometry. The mass spectrometry device  200  is characterized by enabling simultaneous measurement of arrival positions of sample ions  11  (i.e., an original two-dimensional distribution of sample molecules of a sample  10 ) and arrival times (i.e., time-of-flights) of the sample ions  11 . Further, in the conventional MALDI, an image resolution (a spatial resolution) is limited to a crystal size of a matrix. In contrast, according to the mass spectrometry device  200  that performs projection type imaging mass spectrometry using a sample support  2 , the image resolution depends upon diameters of through-holes S, and thus an image resolution (for instance, a image resolution that is lower than or equal to several tens of nanometers) higher than that of the conventional MALDI can be obtained. 
       FIG. 10  is a view illustrating an outline of a mass spectrometry method based on the mass spectrometry device  200 . The mass spectrometry device  200  is different from the mass spectrometry device  100  in that the laser beam application unit  4  is replaced with a laser beam application unit  201 . The laser beam application unit  201  controls application of a laser beam L such that the laser beam L is applied to an imaging target region R 1  on one surface  21   a  of a substrate  21 . The imaging target region R 1  is a region predetermined as a region that is intended to see the two-dimensional distribution of the sample molecules by the imaging mass spectrometry. As illustrated in  FIG. 10 , the imaging target region R 1  is a region that overlaps the sample  10  when viewed in a thickness direction of the substrate  21  (a direction in which the one surface  21   a  and the other surface  21   b  of the substrate  21  face each other). Thus, the sample  10  in the imaging target region R 1  to which the laser beam L is applied is ionized at the same time. Therefore, according to the mass spectrometry device  200 , there is no need to scan many positions like the scanning type mass spectrometry device  100 . 
     Further, the mass spectrometry device  200  is different from the mass spectrometry device  100  in that the detector  3  is replaced with an electrostatic lens (an image formation optical system)  202  and a detector  203 . The electrostatic lens  202  is a lens for forming images of the sample ions  11  at the detector  203 . When the mass spectrometry device  200  is used instead of the mass spectrometry device  100 , the images of the sample ions  11  are formed at the detector  203  by the electrostatic lens  202  in the aforementioned fourth step, and thus the positional information (the two-dimensional distribution) of the sample ions  11  is seen in the detector  203 . 
     In the example illustrated in  FIG. 10 , three types of sample ions  11  (here, sample ions  11 A,  11 B and  11 C whose mass-to-charge ratios are different from one another) included in the sample  10  are specified by arrival times at the detector  203 . Further, the original two-dimensional distribution of the sample molecules of the sample  10  is specified by arrival positions of the sample ions  11  at the detector  203 . 
     According to the mass spectrometry device  200 , the ionization of the sample  10  can be performed by a simple operation of disposing the sample support  2  on the sample  10  while maintaining positional information of the sample  10 . The laser beam application unit  201  applies the laser beam L to the imaging target region R 1  on one surface  21   a , and the detector  203  detects the ionized sample  10  (the sample ions  11 ) in a state where the positional relation of the sample  10  in the imaging target region R 1  is maintained, so that the two-dimensional distribution of the sample molecules can be seen. Further, the image resolution in the imaging mass spectrometry depends on the diameters of the through-holes S of the sample support  2 . Therefore, according to the mass spectrometry device  200 , a high image resolution can be obtained in the imaging mass spectrometry that images a two-dimensional distribution map of the sample molecules. 
     Further, in the mass spectrometry device  200 , the laser beam application unit  201  may control the application of the laser beam L using a portion or the whole of the effective region R of the sample support  2  as the imaging target region R 1 . According to this configuration, the imaging mass spectrometry can be appropriately performed in the effective region R. 
     In the mass spectrometry method based on the mass spectrometry device  200 , the laser beam L is applied to the imaging target region R 1  on one surface  21   a  in the aforementioned third step, and thereby the sample  10  moved from the other surface  21   b  side to one surface  21   a  side via the through-holes S due to a capillary phenomenon is ionized. Further, in the fourth step, the sample  10  ionized in the third step is detected in the state where the positional relation of the sample  10  in the imaging target region R 1  is maintained. According to the mass spectrometry method, the ionization of the sample  10  can be performed by a simple operation of disposing the sample support  2  on the sample  10  while maintaining the positional information of the sample  10 . The two-dimensional distribution of the sample molecules can be seen by applying the laser beam L to the imaging target region R 1  on one surface  21   a  and detecting the ionized sample  10  in the state where the positional relation of the sample  10  in the imaging target region R 1  is maintained. Further, the image resolution in the imaging mass spectrometry depends on the diameters of the through-holes S of the sample support  2 . Therefore, according to the mass spectrometry method, a high image resolution can be obtained in the imaging mass spectrometry that images a two-dimensional distribution map of the sample molecules. 
     While the embodiment of the present invention has been described, the present invention is not limited to the embodiment and can be modified in various ways without departing from the gist thereof. 
     For example, the substrate  21  may be formed of a conductive material such as a semiconductor. In this case, the sample support  2  can omit the conductive layer  23  for giving conductivity to the substrate  21 . When the sample support  2  is not provided with the conductive layer  23 , the sample support  2  is arranged on the sample  10  such that the other surface  21   b  comes into direct contact with the sample  10  in the second step. Even when the substrate  21  is formed of a conductive material in this way and the sample support  2  from which the conductive layer  23  is omitted is used, the same effects as when the sample support  2  having the aforementioned conductive layer  23  is used can be obtained. 
     The ionization of the sample  10  caused by the SALDI method (the first to third steps) can also be used for other measurements and experiments such as ion mobility measurement as well as the imaging mass spectrometry of the sample  10  which is described in the present embodiment. 
     The conductive layer  23  may be provided by vapor deposition or the like to cover at least the one surface  21   a  of the substrate  21 . That is, the conductive layer  23  may not be provided on the other surface  21   b  of the substrate  21  and the inner surfaces of the through-holes S. In this case, the sample support  2  is arranged on the sample  10  such that the other surface  21   b  faces the sample  10  in the second step, and the other surface  21   b  comes into direct contact with the sample  10 . If the conductive layer  23  is provided to cover the surface of the frame  22  and at least the one surface  21   a  of the substrate  21 , the contact between the substrate  21  and the electrode can be made on the frame  22 . 
       FIGS. 11 to 14  illustrate a relation between the hole width of each of the through-holes S and a mass spectrum measured by the mass spectrometry method. Here, as the sample support, a sample support in which the conductive layer  23  (here, Pt) is provided to cover the one surface  21   a  and the surface of the frame  22  without being provided on the other surface  21   b  of the substrate  21  and the inner surfaces of the through-holes S is used. The thickness d 1  of the substrate  21  is 10 μm, and the sample to be measured is a peptide of “mass-to-charge ratio (m/z)=1049.” In  FIGS. 11 to 14 , (a) shows measured results when the hole widths of the through-holes S are set to 50 nm, (b) shows measured results when the hole widths of the through-holes S are set to 100 nm, (c) shows measured results when the hole widths of the through-holes S are set to 200 nm, (d) shows measured results when the hole widths of the through-holes S are set to 300 nm, (e) shows measured results when the hole widths of the through-holes S are set to 400 nm, (f) shows measured results when the hole widths of the through-holes S are set to 500 nm, (g) shows measured results when the hole widths of the through-holes S are set to 600 nm, and (h) shows measured results when the hole widths of the through-holes S are set to 700 nm. In  FIGS. 11 to 14 , the longitudinal axis denotes signal intensity (Intensity) standardized as 100(%) for a peak value. 
     As illustrated in  FIGS. 11 to 14 , even when the hole widths of the through-holes S of the substrate  21  are any one of 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, and 700 nm, a proper spectrum in which a peak can be observed is obtained. In this way, the sample support having the substrate  21  in which the conductive layer  23  is provided on at least the one surface  21   a  is used, and thereby the mass spectrometry can be properly performed. 
       FIG. 15  illustrates a relation between the thickness d 1  (Thickness) of the substrate  21  and signal intensity of a peak measured by the mass spectrometry method. In  FIG. 15 , the longitudinal axis denotes relative signal intensity (Relative intensity) of the case the signal intensity is set to “1” when the thickness d 1  of the substrate  21  is 10 μm. Here, as the sample support, a sample support in which the conductive layer  23  (here, Pt) is provided to cover the one surface  21   a  and the surface of the frame  22  without being provided on the other surface  21   b  of the substrate  21  and the inner surfaces of the through-holes S is used. The hole widths of the through-holes S are 200 nm. The sample to be measured is a peptide of “mass-to-charge ratio (m/z)=1049”. 
     In the measured results, the signal intensity when the thickness d 1  of the substrate  21  is 10 μm is of sufficient magnitude for mass spectrometry. As illustrated in  FIG. 15 , as the thickness d 1  of the substrate  21  becomes smaller, the signal intensity shows a tendency to increase. When the thickness d 1  of the substrate  21  ranges from 3 to 10 μm, sufficient signal intensity is obtained. Meanwhile, in terms of securing strength of the substrate, the thickness d 1  of the substrate  21  is preferably large. For this reason, the thickness d 1  of the substrate  21  may be set to 5 to 10 μm. Thereby, the strength of the substrate  21  can be maintained, and sufficient signal intensity can be obtained in the mass spectrometry. 
     In the embodiment, the form in which the frame  22  of the sample support  2  is fixed to the sample stage  1  by the adhesive tape T has been described, but a form of fixing the sample support  2  to the sample stage  1  is not limited to the form. Hereinafter, a variation of the form of fixing the sample support  2  to the sample stage  1  will be described using  FIGS. 16 to 18  along with first to third modifications of the sample support  2 . In  FIGS. 16 to 18 , the conductive layer  23  and the through-holes S are not illustrated. In  FIGS. 17 and 18 , the bonding layer G for bonding the frame and the substrate is also not illustrated. 
     (First Modification) 
     As illustrated in  FIG. 16 , a sample support  2 A according to a first modification is mainly different from the sample support  2  in that a frame  22  is not provided for a substrate  21  and an adhesive tape T is directly stuck on one surface  21   a  of the substrate  21 . The adhesive tape T is stuck on an outer edge of the one surface  21   a  such that an adhesive face Ta thereof faces the one surface  21   a  of the substrate  21 , and the adhesive tape T has a portion that extends beyond an outer edge of the substrate  21 . Thereby, as illustrated in  FIG. 16 , the adhesive face Ta can be stuck on the outer edge of the substrate  21  and a placement surface  1   a  of a sample stage  1 . As a result, the sample support  2 A is fixed to the sample stage  1  by the adhesive tape T. 
     According to the sample support  2 A, for example when mass spectrometry of a sample  10  whose surface has concavities and convexities is performed, a follow-up characteristic of the substrate  21  for the sample  10  can be improved. 
     When the sample stage  1  has conductivity, the sample stage  1  and the sample support  2 A (particularly, a conductive layer  23  provided on the one surface  21   a  of the substrate  21 ) are electrically connected via the adhesive tape T having conductivity. Therefore, as illustrated in  FIG. 16 , in the state where the sample support  2 A is fixed to the sample stage  1  via the adhesive tape T, a predetermined current is applied to the sample stage  1 , and thereby a predetermined voltage can be applied to the substrate  21 . 
     The sample support  2 A may be distributed in a state where the adhesive tape T is stuck on the outer edge of the substrate  21  and an adhesive protection sheet is provided on the adhesive face Ta of the portion that extends beyond the outer edge of the substrate  21 . In this case, a user of the sample support  2 A releases the adhesive protection sheet immediately before the sample support  2 A is fixed to the sample stage  1 , and sticks the adhesive face Ta on the placement surface  1   a , and thereby preparation of the mass spectrometry of the sample  10  can be easily performed. 
     (Second Modification) 
     As illustrated in  FIG. 17 , a sample support  2 B according to a second modification is mainly different from the sample support  2  in that a frame  122  having a portion that extends beyond an outer edge of a substrate  21  is provided. When the sample support  2 B is carried by this frame  122 , damage to an end of the substrate  21  can be properly suppressed. Further, as illustrated in  FIG. 17 , insertion holes  122   a  for inserting screws  30  are provided in the portion of the frame  122  which extends beyond the outer edge of the substrate  21 . In this case, for example when a sample stage  1 A having screw holes  1   b  at positions corresponding to the insertion holes  122   a  is used, the sample support  2 B can be reliably fixed to the sample stage  1 A by screwing. To be specific, the screws  30  are inserted into the insertion holes  122   a  and the screw holes  1   b , and thereby the sample support  2 B can be fixed to the sample stage  1 A. 
     When the sample stage  1 A has conductivity and when the screws  30  have conductivity, the sample stage  1 A and the sample support  2 B (particularly, a conductive layer  23  formed on the frame  122 ) are electrically connected via the screws  30 . Therefore, as illustrated in  FIG. 17 , in a state where the sample support  2 B is fixed to the sample stage  1 A via the screws  30 , a predetermined current is applied to the sample stage  1 A, and thereby a predetermined voltage can be applied to the substrate  21 . 
     (Third Modification) 
     As illustrated in  FIG. 18 , a sample support  2 C according to a third modification is mainly different from the sample support  2  in that an adhesion layer  24  having one adhesive face  24   a  facing a direction directed from one surface  21   a  to the other surface  21   b  is provided at an outer edge of the other surface  21   b  of a substrate  21 . The adhesion layer  24  is, for instance, a double-sided tape or the like that has a thickness predetermined depending on a thickness of a sample  10  to be measured. For example, the other adhesive face  24   b  of the adhesion layer  24  is previously stuck on the outer edge of the other surface  21   b  of the substrate  21 , and the one adhesive face  24   a  of the adhesion layer  24  is stuck on a placement surface  1   a  when the sample support  2 C is fixed to a sample stage  1 . According to the sample support  2 C, a configuration in which the sample support  2 C is fixed to the sample stage  1  can be simplified. 
     When the sample stage  1  has conductivity and when the adhesion layer  24  has conductivity, the sample stage  1  and the sample support  2 C (particularly, the substrate  21 ) are electrically connected via the adhesion layer  24 . Therefore, as illustrated in  FIG. 18 , in a state where the sample support  2 C is fixed to the sample stage  1  via the adhesion layer  24 , a predetermined current is applied to the sample stage  1 , and thereby a predetermined voltage can be applied to the substrate  21 . 
     The sample support  2 C may be distributed in a state where the adhesive face  24   b  of the adhesion layer  24  is stuck on the outer edge of the other surface  21   b  of the substrate  21  and an adhesive protection sheet is provided for the adhesive face  24   a . In this case, a user of the sample support  2 C releases the adhesive protection sheet immediately before the sample support  2 C is fixed to the sample stage  1 , and sticks the adhesive face  24   a  on the placement surface  1   a , and thereby preparation of the mass spectrometry of the sample  10  can be easily performed. 
     The sample supports  2 ,  2 A,  2 B, and  2 C according to the embodiment and the modifications may be baked after the conductive layer  23  is formed. The step of manufacturing a sample support in the embodiment may include a baking step of baking the sample support after the conductive layer  23  is formed. When the frame  22  is provided, the baking step is performed on a sample support having the substrate  21  the frame  22 , and the conductive layer  23 . When the frame  22  is omitted, the baking step is performed on a sample support having the substrate  21  and the conductive layer  23 . 
     By performing this baking step, crystallinity of the conductive layer  23  (for instance, Pt) can be improved, and a sample support that is more suitable for mass spectrometry can be obtained. Here, the baking of the sample support is preferably performed such that a diffraction peak of a crystal of a conductive material (here, Pt) forming the conductive layer  23  is shown in an X-ray diffraction (XRD) measurement for the conductive layer  23  (the sample support) after the baking. Here, the expression of the “diffraction peak of the crystal of the conductive material is shown” means that a diffraction pattern (peak intensity or the like) of the crystal of the conductive material is more clearly shown than measured results obtained by the XRD measurement for the sample support before the baking. 
     (a) of  FIG. 19  illustrates a mass spectrum measured by the mass spectrometry device  100  having the sample support before being baked. On the other hand, (b) of  FIG. 19  illustrates a mass spectrum measured by the mass spectrometry device  100  having the sample support after being baked at a baking temperature of 400° C. Measurement conditions (a type of sample, a configuration of the sample support, etc.) other than the presence and absence of the baking are the same between (a) and (b) of  FIG. 19 . The longitudinal axes of (a) and (b) of  FIG. 19  denote relative signal intensity of the case signal intensity of a peak (i.e., a peak value of the graph in (b) of  FIG. 19 ) is set to “100” when the sample support after the baking is used. As illustrated in  FIG. 19 , the signal intensity can be further improved in mass spectrometry by using the sample support after the baking than when using the sample support before the baking. In this way, a sample support that is more suitable for the mass spectrometry can be obtained by performing the baking step. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  Sample stage 
               2 ,  2 A,  2 B,  2 C Sample support 
               3 ,  203  Detector 
               4 ,  201  Laser beam application unit 
               10  Sample 
               11  Sample ion 
               21  Substrate 
               21   a  One surface 
               21   b  Other surface 
               22 ,  122  Frame 
               23  Conductive layer 
               24  Adhesion layer 
               24   a ,  24   b  Adhesive face 
               30  Screw 
               122   a  Insertion hole 
               100 ,  200  Mass spectrometry device 
             L Laser beam 
             R Effective region 
             R 1  Imaging target region 
             S Through-hole 
             T Adhesive tape 
             Ta Adhesive face