The present invention provides an authenticating apparatus for employing a living-body such as, for example, a fingerprint and a palm print, thereby to make personal authentication, and for purpose of allowing a detection as to whether or not a subject is a living-body to be made securely, thus making it possible to securely identify a non-living body such as, for example, an artificial finger made of gummi, the apparatus comprises and is configured of: an image obtaining means for continuously obtaining images of an integument surface of the living-body, which moves while touching an obtaining plane; and a secretion product detecting means for detecting existence of a secretion product to be secreted from an exocrine gland of the integument surface of the living-body, based upon a plurality of the images obtained continuously by this image obtaining means.