It is designed to provide a kind of biological information measurement device, which ensure that compactness, is not intended to fall off finger, and does not tend to weaken even blood flow by growing measurement. Biological information measurement device, obtain the biological information of patient, by receive from the finger of light unit that light source emit and reception light unit and subject be inserted between space in, light source unit and optical receiver apparatus, including a main part, the main part and probe that probe and interconnecting piece are electrically connected to each other. The main part has a shell, and shell includes battery portion and circuit, which is connected to shell and includes at least one first proximal phalanx part and middle phalanx Toe Transplantation for Segmental Finger for installing mounted member the first fixing piece. There is the probe second mounting portion to include a light source unit and optical receiver apparatus and include distal phalanx Toe Transplantation for Segmental Finger for installation into the second mounted member.
