An image creator (33) creates an optical image and a mass spectrometric (MS) image for each m/z for a measurement area on the same sample, and an image alignment processor (34) equalizes resolutions and aligns the images. A regression analysis executer (35) performs partial least squares regression (PLS) to create a regression model, using a matrix based on the MS imaging data as an explanatory variable and a matrix, which has a luminance value for each pixel as an element and has been created from the optical image, as an explained variable. An image creator (33) applies the explanatory variable, that is, a signal intensity value for each mass-to-charge ratio value in each pixel of the MS imaging data, to the regression model to create an estimation image. A display processor (39) displays a reference image and the estimation image on a screen of a display unit (5). Thus, an operator can confirm the degree of similarity in distribution between the MS image and the optical image. Consequently, the accuracy of the created regression model can be evaluated.