An object is to provide a spectroscope and a spectrum laser microscope capable of carrying out sensitivity correction of a multi-channel photodetector with real time. The spectrum laser microscope 100 includes a laser microscope 101 and a spectral analyzer 103 having a multi-channel photodetector 13 composed of a plurality of photodetectors 13i for detecting spectral distribution of the light from the laser microscope 101. Sensitivity fluctuation of the plurality of photodetectors 13i is calculated from a first luminance data detected before shifting relative position between the spectra and the multi-channel photodetector 13 and a second luminance data detected after shifting. Then, the first luminance data or the second luminance data is corrected.