Biometric data acquisition device, biometric data acquisition method and biometric authentication device

A biometric data acquisition device for acquiring data of a living body by irradiating the living body with light includes: a light source unit that emits light to the living body; a plurality of light receiving elements that receive transmitted light or reflected light, which is transmitted through the living body or reflects from the living body, respectively, by irradiating the living body with the light from the light source unit; an openable and closable gate provided for each of the plurality of light receiving elements; and an opening and closing control unit that controls opening and closing of the gate so as to make uniform intensities of light received by the plurality of light receiving elements.