An imaging mass spectrometer includes an analysis executing section that executes MSn analysis for a target component on each of a plurality of micro regions set within a two-dimensional measurement region on a sample to collect data; an ion selecting section that selects a plurality of kinds of product ions derived from, or assumed to be derived from, the target component based on at least a part of the data collected by the analysis executing section; and a distribution image creating section that determines, using signal strength of each of the kinds of product ions in each micro region within the measurement region. a small region in which all of the kinds of product ions are detected or a small region assumed to have high reliability that all of the kinds of product ions are derived from the target component, and creates a distribution image visualizing the small region.