A bone density meter including a light emission unit which emits light toward a surface of a user's body. A light reception unit receives the light emitted from the light emission unit toward the body surface and propagated in a portion of the body that includes bone. A bone density computation unit determines the bone density based on the amount of light received by the light reception unit. The light emission unit emits light toward the body surface at a portion having a thin subcutis, and the light reception unit receives the light propagated in the body through the portion at which the subcutis is thin.