Patent ID: 8324569

Claim:
A mass spectrometer capable of an MS/MS analysis for each of a plurality of micro areas defined within a two-dimensional area on a sample, which is characterized by comprising: a) an MS analysis conducting means for performing an MS analysis for each of the micro areas within a predetermined two-dimensional area on a sample to collect MS spectrum data; b) a substance-of-interest selection means for allowing an operator to refer to the aforementioned MS data and select one or more substances of interest or m/z value thereof; c) an MS/MS analysis conducting means for performing an MS/MS analysis using the m/z value of the selected one or more substances of interest as a precursor for each of the micro areas within the predetermined two-dimensional area, to collect MS/MS spectrum data; d) an area extraction means for extracting, for each of the aforementioned one or more substances of interest, one or more micro areas in which the substance concerned is present, based on the MS spectrum data; e) an average spectrum calculation means for selecting, from the aforementioned MS/MS spectrum data, the MS/MS spectrum data of the aforementioned one or more micro areas extracted by the area extraction means, and for calculating an average MS/MS spectrum for each substance of interest, using the selected MS/MS spectrum data; and f) an identification means for identifying each substance of interest by using the average MS/MS spectrum of the substance concerned.