To provide an optical fat measuring device and an optical fat measuring method for highly accurately measuring the state of fat with excellent reproducibility.

The optical fat measuring device comprises: a molding part 3 which impresses such a pressure that subcutaneous fat 2 under a living body surface 1 is not deformed any more to the living body surface 1 and is provided with a plurality of light source parts 6 arranged on the living body surface including a part where the pressure is impressed and a plurality of light receiving parts arranged, a prescribed distance away from light emission parts, on the living body surface including the part where the pressure is impressed; a plurality of light source elements for emitting light; a photodetector 8 for measurement and a photodetector 9 for correction for receiving the light; and an arithmetic part 10 for calculating the state of the subcutaneous fat 2 of the living body on the basis of the reception quantity of the light of the photodetector.