1. A method of analyzing mass analysis data for selecting a component similar to a target component from one or more unknown sample components, based on a result of an MS n analysis in which a precursor ion originating from each of the sample components is dissociated into fragment ions by (n−1) steps (where n≧2) and then the fragment ions are subjected to a mass-analyzing process, wherein the method comprises: a) an extraction step for extracting predetermined parameters from spectral data obtained by the MS n analysis and MS n spectral data of the target component; b) a similarity evaluation step for evaluating a similarity value between the target component and each of the sample components by multivariable analysis of the parameters; and c) a selecting step for selecting a component similar to the target component based on the similarity value.