A biological measurement device comprises: a probe that has a plurality of light input parts that input light to a site to be measured, and a plurality of light receiving parts that receive measurement light outputted from the site to be measured, said probe having an abutting surface that is pressed against the site to be measured； and an arithmetic unit that calculates internal information on the basis of a detection result for the measurement light obtained for each combination of the light input parts and the light receiving parts. At the abutting surface, the plurality of light input parts and the plurality of light receiving parts constitute part of a lattice along a first direction and a second direction, which are mutually orthogonal, said lattice having an interval d. At least a portion of the plurality of light receiving parts are set apart from the light input parts by a distance A × d (A is an integer of 2 or more) in the first direction and the second direction. At least a portion of the plurality of light input parts are set apart from the light receiving parts by the distance A × d in the first direction and the second direction. In the combinations, the interval between the light input parts and the light receiving parts is A × d.La présente invention concerne un dispositif de mesure biologique qui comprend : une sonde qui comporte une pluralité de parties d'entrée de lumière qui transmettent de la lumière à un site à mesurer, et une pluralité de parties de réception de lumière qui reçoivent une lumière de mesure transmise depuis le site à mesurer, ladite sonde comportant une surface de butée qui est pressée contre le site à mesurer ； et une unité arithmétique qui calcule des informations internes sur la base d'un résultat de détection pour la lumière de mesure obtenue pour chaque combinaison des parties d'entrée de lumière et des parties de réception de lumière. Au niveau de la surface de butée, la pluralité de parties d'entrée de lumière et la plur
