A periphery monitoring apparatus capable of photographing a vicinity of a vehicle without impairing the outer appearance of the vehicle includes a light source configured to be provided in the vehicle for illuminating the periphery of the vehicle, and a camera photographing a condition of the periphery of the vehicle with an optical axis changed by a mirror toward the underside of the circumferential edge of the vehicle illuminated by at least a portion of light irradiated from the light source reflected by the mirror configured to be disposed on the outer side of the circumferential edge of the vehicle.