Personal identification is implemented by picking up finger vein patterns when the user naturally grasps a grip such as doorknob. The device for personal identification has a light source provided to irradiate light on the finger from the palm side, a camera to pick up the vessel image of the finger, and a processor to extract features of the vessel from the image and compare the obtained features with the registered ones. The camera picks up the light that exits from the backside of the finger after penetrating it.