1. A data processing apparatus for analyzing overlapping peaks on a multi-channel chromatogram, comprising: a computation unit for adjusting a dispersion function by a deconvolution operation with changing a deconvoluting parameter from said dispersion function until a multivariate analysis uniquely has a solution, determining a multi-channel chromatogram deconvoluted by using a dispersion function adjusted by said deconvolution operation, and analyzing overlapping peaks on said multi-channel chromatogram deconvoluted by said dispersion function.