A method for analyzing MALDI mass spectrometry data includes: calculating m/z values respectively corresponding to peaks in amass spectrum, from data corresponding to the mass spectrum acquired by MALDI mass spectrometry performed on a sample; and performing at least one of calculations (a) and (b), based on the m/z values and information on kinds of ions possibly generated from the sample in the mass spectrometry, where calculation (a) includes assuming that ions respectively corresponding to the peaks are first ions singly charged, and calculating m/z of second ions respectively corresponding to the first ions and being multiply charged, and calculation (b) includes assuming that ions respectively corresponding to the peaks are first ions that are multiply charged ions, and calculating m/z of second ions respectively corresponding to the first ions and being singly charged.