A lamp device of the present invention includes a lamp unit comprised of a light source and a reflector having a mirror part which reflects light from the light source forward, and a radar unit arranged behind the lamp unit. The radar unit is arranged so that at least a portion of the mirror part falls within a radiation range of an electromagnetic wave radiated from the radar unit. The mirror part includes a resin member and a light reflecting surface formed on a surface of the resin member and comprised of an island-shaped metallic layer having metallic luster.
