A mass spectrometer includes: a chamber; a support that, in a state in which, in a sample support body that includes a substrate in which a plurality of through-holes open in first and second surfaces are formed and a conductive layer that is at least provided on the first surface, the second surface thereof is in contact with a sample, supports the sample and the sample support body; a laser beam irradiation part that irradiates the first surface with a laser beam; a voltage application part that applies a voltage to the conductive layer; an ion detection part that, detects the ionized components of the sample in a space inside the chamber; a first light irradiation part that irradiates the sample with a first light from a side of the substrate; and an imaging part that obtains a reflected light image of the sample by the first light.