Provided is a sample support body that includes a substrate and an ionization substrate. The ionization substrate has a measurement region for dropping a sample on a second surface. A plurality of through-holes that open in a first surface and the second surface are formed in at least the measurement region of the ionization substrate. A conductive layer is provided on peripheral edges of the through-holes on at least the second surface. At least a part of the substrate which is adjacent to the ionization substrate is formed to enable the sample to move to the inside of the substrate.