A number of analytes are divided into groups based on at least either the elution position determined by silica gel column chromatography under the same condition or the partition ratio in a hexane-acetonitrile partition method. To each group, a compound obtained by labeling one of the compounds in the group by deuterium and/or carbon 13 is assigned as the surrogate. After those surrogates are added as internal standard substances to a standard sample for the creation of calibration curves, a GC/MS analysis for the sample is performed and a calibration curve is created for each analyte. The created calibration curves are organized into a database (35). In the measurement of an unknown sample, the same set of surrogates are added to the sample and the GC/MS analysis is performed. A quantitative determination processor (34) determines the quantity of each analyte by comparing a peak area ratio calculated from the analysis result with a calibration curve read from the database (35). This method requires a smaller number of standard substances to be prepared and a lower amount of cumbersome tasks to be performed by analysis operators while ensuring a high level of quantitative accuracy in the simultaneous multicomponent analysis.