Mass spectrometry data processing device

A mass spectrometry data processing device that identifies compounds contained in a sample based on mass spectrum data obtained by performing mass spectroscopy of said sample, comprising:

• a) a compound information memory that stores the theoretical mass of a variety of compounds, and, when a compound is ionized under designated ionization conditions, also storing the designated ionization conditions together with a corresponding compound;
• b) an adduct information memory that stores the theoretical mass of adduct ions adducted to a compound during ionization, correlated to the adduct ion, and, when adduction to a compound occurs under designated ionization conditions, also stores the ionization conditions correlated to the adduct ion;
• c) a condition input portion for the user to input ionization conditions during mass spectrometry;
• and
• d) a compound candidate search portion that finds a measured mass-to-charge ratio of peaks to be identified on a mass spectrum obtained by mass spectrometry and, based on said measured mass-to-charge ratio and the ionization conditions input via the condition input portion, extracts compound and adduct ion combination candidates corresponding to the peaks from among combinations of adduct ions stored in the adduct information memory and compounds stored in the compound information memory.