A biometric authentication device including a housing, a light source unit that is installed on an upper surface of the housing and includes a light source, and an opening that is provided in the upper surface of the housing and located below the light source, and an imaging unit that is disposed inside the housing is disclosed. In the device, an optical axis of the light source intersects with a longitudinal direction of the housing, and the imaging unit images a user's biometric feature irradiated with an irradiation light from the light source through the opening.