1. A biometrical feature inputting system comprising: an imager placed in front of a finger, for imaging an image of a front face of said finger, and an image of at least one lateral face of said finger; a reflector placed on a side of said at least one lateral face of said finger, for reflecting an image of said at least one lateral face of said finger to said imager; and a synthesizer for digitally applying mirror inversion to said reflected image of said at least one lateral face of said finger, and synthesizing a mirror-inverted image of said reflected image and an imaged image of said front face of said finger.