To obtain more exact fluorescence gain images by enhanced measuring accuracy of fluorescent gain in a fluorescence image measurement method and equipment.

A fluorescence gain image is obtained by a fluorescence gain image calculator 53 based on the calibrated excitation light corresponding to the reference light image data Drs and fluorescence image data Dj, Drs being obtained by calibrating a reference light image data Ds with the reference light calibrator 46 by performing such calibration calculation that it would be obtained if the irradiation intensity distribution of the reference light Sa that is used to obtain reference light image data Ds is the same as that of excitation light Re, based on the irradiation intensity distribution of excitation light Re memorized in the light standard excitation light image memory 41 and the irradiation intensity distribution of reference light Sa memorized in the standard reference light image memory 42.