Abstract: A mass spectrometer includes a beam radiator radiating a beam to a sample. A laser radiator radiates laser light onto an irradiation surface of a surface of the sample irradiated with the beam or above the irradiation surface. The laser radiator splits the laser light into at least first light and second light. The laser radiator adjusts a polarization state, a length of an optical path, or a direction of the optical path of at least either the first light or the second light to condense the first light and the second light onto the irradiation surface or above the irradiation surface. A detector detects particles discharged from the sample.