A biometric authentication apparatus, for enabling to detect a counterfeit when counterfeited information is inputted, thereby preventing from a mischievous authentication, comprises: a registration unit for register a biometric information pattern; a lighting unit for irradiating a lighting upon a photographing target; an image sensor for photographing the photographing target, upon which the lighting is irradiated by the lighting unit; an authentication process unit for extracting the biometric information pattern from a video signal, being outputted from the image sensor, and thereby comparing it to a biometric information pattern, being registered in the registration unit; and a control unit for controlling a lighting intensity of the lighting irradiated by the lighting unit, wherein the control unit changes the lighting intensity of the lighting irradiated by the lighting unit, and determines on whether the photographing target is a living body or not, with using the change of brightness of the video signal outputted by the image sensor.