A personal identification device including: an image pickup unit; a light source which emits the light adapted to be transmitted through a finger and incident on said image pickup unit; an image operating unit which generates a pattern from an image picked up by said image pickup unit and matching the pattern of said image with a pattern registered in advance; a storage which holds said registered pattern; a guide unit which indicates the position where the image of said finger is picked up; and a detection unit which detects a contact between said finger and said guide unit.