The present invention addresses the problem of providing a brain function measurement device and a brain function measurement method capable of eliminating or minimizing calibration operations. To solve this problem, a brain function measurement device is provided which has: a first light emission probe S1 for emitting light to the brain of a subject; a first light detection probe D1 which is disposed adjacent to the first light emission probe S1 and detects light emitted from the first light emission probe S1 and reflected by the brain; a second light emission probe S2 which is disposed adjacent to the first light detection probe D1 and emits light to the brain of the subject; a second light detection probe D2 which is disposed adjacent to the second light emission probe S2 and detects light emitted from the second light emission probe S2 and reflected by the brain; and a control unit 3 which adjusts the amount of light emitted by the second light emission probe S2 so that the amount of light measured in a channel between the first light detection probe D1 and second light emission probe S2 matches an observed value observed in a channel between the first light emission probe S1 and first light detection probe D1, and also adjusts the amount of light detected by the second light detection probe D2 so that the amount of light measured in a channel between the second light emission probe S2 and second light detection probe D2 matches the observed value.
BRAIN FUNCTION MEASUREMENT DEVICE AND BRAIN FUNCTION MEASUREMENT METHOD