An apparatus for detecting and identifying a biological object. A transparent plate has a first surface onto which a light beam is projected and a second surface onto which a biological object to be detected and identified is placed. The light beam projected toward the first plate surface is transmitted through the plate and toward the object on the second surface, from which the light beam is reflected and retransmitted through the plate toward and through the first surface thereof and received and detected by an optical detector. The detection of a biological object is confirmed by comparing the change of the wavelength characteristics of the reflected and detected light beam in a predetermined time sequence according to the object being first placed upon and then pressed upon the second surface of the transparent plate with respective, known such characteristics thereof.