A subcutaneous fat thickness measuring apparatus includes: a light source section that irradiates a surface of a living body with plural light rays having different central wavelengths; a light receiving section that receives the plural light rays of different wavelengths emerging from the surface of a living body and determining the quantities of the plural light rays received; and a calculator section that calculates the thickness of subcutaneous fat of the surface of a living body from the quantities of the plural light rays received measured by the light receiving section using a previously determined relationship among subcutaneous fat thicknesses, blood concentrations in subcutaneous fat and quantities of plural light rays having different central wavelengths.