1. An organism authenticating apparatus comprising a means that fixes the position of a hand or a finger of a hand, an infrared ray radiating means that radiates infrared rays, an infrared ray image input means that is placed at the opposite side of said hand or said finger of a hand with regard to said infrared ray radiating means, an organism recognizing means that recognizes that the organism is live, a processing means that processes data that are inputted by said infrared ray image input means so that it collates them with image data that are registered in advance and an output means that outputs the result of processing carried out by said processing means.