One of the purposes of the present invention is to provide a biogenic substance concentration measuring method with improved measuring accuracy. An embodiment of the present invention provides a method for measuring a concentration of a biogenic substance contained in a living body, the method comprises steps of preparing a measuring device, wherein the measuring device comprises a light source, an optical filter, and a light receiver; irradiating a substantially-parallel light from the light source onto a particle chip implanted in a skin though a position on the surface of the skin to generate a reflected light; inclining the light source and calculating the concentration of the biogenic substance on the basis of the difference of signals before and after the inclination.