In a biophotonic measurement device based on the principles of near-infrared spectroscopy (NIRS), in order to realize appropriate conditions in any light-source/detector arrangement and various required specifications, a photoirradiation module 13 including a light source 101, a photodetection module 14 including a photodetector 102, and a central control/analysis unit 18 are provided. The central control/analysis unit 18 acquires correspondence relations between each of photodetection units and photoirradiation units by using a correspondence acquiring unit 19. The photoirradiation module 13 and the photodetection module 14 switch signal detection methods at each measurement point by utilizing an evaluation function value determined by detection output of the photodetector 102 so that the plurality of signal detection methods are mixable, and the high-precision and optimum biophotonic measurement device is realized.
