A region-of-interest setting unit (41) establishes a two-dimensional region of interest on a sample and a plurality of measurement points (minute regions) in the region in response to a user instruction. A measurement region setting unit (42) establishes separate measurement points each in positions completely non-overlapping with the measurement points in the vicinity of the measurement points in the region of interest, and sets a measurement region including the plurality of separate measurement points. When the user instructs a measurement method individually for the region of interest and the measurement region from an input unit (5), a measurement method assignment unit (44) assigns and stores a measurement method for each region. An analysis control unit (3) executes mass spectrometry in accordance with the measurement method assigned for each measurement point in the region of interest and the measurement region and stores data in a data storage unit (21). The measurement region is in a position slightly offset from the region of interest, and the two-dimensional distribution of components is considered to be substantially the same between the measurement region and the region of interest. It is therefore possible to acquire a high-quality MS imaging images with respect to regions of interest based on different measurement methods with almost no adverse effects due to depletion of components or a matrix by laser light irradiation.