Abstract: Provided is a lamp device including: a housing, which is a part to be attached to a vehicle; a lamp unit; a radar unit having an antenna which transmits a radar wave and receives a reflection wave from an object; a light-transmissive cover which is attached to cover a front surface of the housing so as to accommodate therein the lamp unit and the radar unit, and through which the radar wave passes; and a radio wave absorption section provided on a surface of the housing that faces the light-transmissive cover or on a surface on the opposite side therefrom.