In a biophotonic measurement apparatus using a probe having multiple source-detector distances (SD distances) for separating light absorption changes in superficial layers and deep layers of biological tissue on the basis of near infrared spectroscopy, light reception sensitivity for various subjects/various regions is stabilized by adjusting the amount of attenuation of the light that is transmitted or received. The biophotonic measurement apparatus comprises: a light source； a detector for detecting light irradiated on an irradiation point of a subject from the light source and propagated inside the subject； a light attenuation amount-adjusting means disposed on the light path between the light source - subject or light detector - subject； an analysis unit for signal analysis； and a display unit for displaying the analysis results. The light source and the detector are each disposed so that there are two or more SD distances, which are defined as the distance between an irradiation point and a detection point. The analysis unit analyzes the measured signals and calculates the light attenuation adjustment amount for fitting each amount of received light within a specified range. From the analysis results, the light attenuation amount-adjusting means adjusts the respective light attenuation amounts by changing the amount of light entering the detector.La présente invention concerne un appareil de mesure biophotonique utilisant une sonde comprenant une pluralité de distances source-détecteur (distances SD) pour la séparation de changements d'absorption de lumière dans des couches superficielles et des couches profondes de tissu biologique sur la base de la spectroscopie proche infrarouge, dans lequel la sensibilité de réception de lumière pour divers sujets/diverses régions est stabilisée par l'ajustement de la quantité d'atténuation de la lumière qui est transmise ou reçue. L'appareil de mesure biophotonique comporte : une source lumineuse ； un détecteur pour la dét
