A personal authentication apparatus, being small/thin and also enabling to position a vital body with high accuracy and comprises: a first light source and a second light source and each of which is configured to irradiate infrared rays and detector portion, which is configured to detect the infrared rays irradiated from the first and second light sources upon a vital body, whereby detecting a picture having characteristic information of the vital body from the infrared rays detected by the detector portion and executing a personal authentication, wherein irradiation is made from the first and second light sources upon the vital body, and position information of the vital body is detected from the infrared rays detected by the detector portion and thereby executing non-contacting positioning of the vital body.
