To provide an MRI apparatus or a magnetic resonance imaging apparatus which reduces the time required for fitting processing for MRS (magnetic resonance spectroscopy) data analysis of a frequency domain where a base line correction is performed and has features of MRS measurement with enhanced fitting accuracy and of the processing and the analysis of measured spectral data of NMR (nuclear magnetic resonance).

A discrimination analysis (a multivariate analysis) is applied to MRS data where the base line correction is performed to separate the MRS data of the frequency domain into noise regions and signal regions. As the result, the frequency domain is divided into a plurality of the signal regions and noise regions. The fitting is performed only in the signal region, and the functions used for a sum of model functions are limited to only a Gaussian function and a Lorenz function which keep a resonant frequency present in the signal region where the fitting is performed. By the limit, the number of parameters subjected to the fitting is reduced, and the time required for the fitting processing is reduced.