A photobiological measurement apparatus 1 may include a second received light quantity information calculation unit 33 for calculating measurement data relating to cerebral activity, a data display controller for displaying the measurement data for a specified area of a subject's brain, is characterized: is being provided with a reference light-receiving probe 14, which is disposed at a position separated by a first setting distance r1 from the light-transmitting prober 12 that is shorter than a second setting distance r2, and a first received light quantity information calculating unit 32, which calculates skin blood flow data relating to the skin blood flow using first received light quantity information ΔA1 from the light transmitting probe 12 to the reference light-receiving probe 14, and in displaying the skin blood flow data at a specified position of the subject's scalp by indicating the measurement position on the subject's scalp and displaying the skin blood data.