A proximity detection device detects the proximity of an object using a light emitting element and a light receiving element that receives reflected light of irradiation light from the light emitting element reflected by the object. A mirror is provided near the light emitting element to reflect part of the irradiation light emitted from the light emitting element toward an area at which the irradiation light from the light emitting element does not sufficiently arrive, and a mirror is provided near the light receiving element to enable reception of the reflected light from the light emitting element in a wide range.