A prism includes a large surface at least a portion of which is a placing region for a finger, a small surface parallel to the large surface, and first and second inclined lateral surfaces. A light source emits light to the first inclined lateral surface. A first imaging sensor arranged below the small surface receives a light transmitted from the light source through the small surface to obtain a first image. A second imaging sensor receives a light transmitted from the light source through the second inclined lateral surface to obtain a second image of which fingerprint pattern contrast is enhanced more than that of the first image. An infrared light source emits infrared ray light to the finger. The first imaging sensor receives the infrared ray light transmitted from the infrared light source through the small surface to obtain a third image for a blood vessel of the finger.