To provide a technique capable of handling quantitative data in a spectrum type microparticle measurement device without causing deterioration of the SNR. The present technology provides a microparticle measurement spectrometer including a spectroscopic element that disperses light emitted from microparticles flowing through a flow path, and a photoelectric conversion array that has a plurality of light receiving elements having different detection wavelength ranges and converts optical information obtained by the light receiving elements into electrical information, in which the photoelectric conversion array has a uniform output of all channels when light with which the amount of light per unit wavelength becomes same is incident.