A body fat measuring apparatus is provided with a light emitting device 1 for projecting light rays to a subject's tissue, light receiving devices 3 and 4 for detecting a transmitted light ray having passed through the subject's tissue and/or a reflected light ray reflected inside the subject's body, and a CPU 6 for calculating the subject's subcutaneous fat thickness and/or body fat percentage by performing an operation by use of the detection results of the light receiving devices 3 and 4. The light receiving devices 3 and 4 are situated at different distances from the light emitting device 1.