1. A mass spectrometer comprising: a) a sample holder for holding a sample; b) an observation unit for observing a surface of the sample held by the sample holder; c) an ionization unit for ionizing a component at a specified position on the sample held by the sample holder; d) a mass analyzer for mass analyzing an ion generated by the ionization unit; e) a sample cutter for cutting a portion of the sample held by the sample holder to expose a sample analysis surface which is a target of an ionization by the ionization unit; and f) a moving unit for moving the sample holder in such a manner that the sample is sequentially carried to an observation position where the sample can be observed by the observation unit, a cutting position where the sample is cut by the sample cutter, and an analysis position where an ionization can be performed by the ionization unit.