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