An organism optical measurement device having a light transmitter/receiver control unit for obtaining measurement data concerning brain activities and a measurement data display control unit for displaying the measurement data. The organism optical measurement device is further provided with a head surface appearance image acquiring unit for acquiring a head surface appearance image of a subject, a head surface appearance image display control unit for displaying the head surface appearance image, and a measurement-related position calculating unit for calculating the measurement-related position in the head surface appearance image from which the measurement data is obtained when an input device specifies the positions in the head surface appearance image corresponding to the positions of a light transmitting probe and a light receiving probe disposed on the head surface of the subject. The measurement data display control unit displays the measurement data in the measurement-related position in the head surface appearance image.
