A microorganism identification method according to the present invention includes a step of subjecting a sample containing microorganisms to mass spectrometry to obtain a mass spectrum, a step of reading a mass-to-charge ratio m/z of a peak derived from a marker protein from the mass spectrum, and an identification step of identifying which bacteria of serovar of Salmonella genus bacteria the microorganisms contained in the sample contain, based on the mass-to-charge ratio m/z, in which at least one of two types of ribosomal proteins S8 and Peptidylpropyl isomerase is used as the marker protein.