A photoradiation device of the present invention includes a light emitting unit that radiates radiation light a reflection unit that reflects the radiation light and a light guide unit that guides the reflected radiation light to an irradiation target body. The light guide unit includes a first light guide face and a second light guide face. The reflection unit includes a first reflection unit that reflects a part of the radiation light to the first light guide face, a second reflection unit that reflects entering light to the second light guide face, and a third reflection unit formed of a main body part provided with a transmission unit which reflects a part of remainder of the radiation light to the second reflection unit as the entering light. The third reflection unit is disposed with a transmission unit side inclined toward a light emitting unit such that the shorter a distance of the transmission unit to the light emitting unit, the larger an amount of transmission light of the radiation light. Thus, a photoradiation device that irradiates a plurality of irradiated faces with a single light emitting unit is achieved.
