A radar device comprises an antenna portion, a radome, and a housing. The antenna portion includes an antenna surface provided with one or more antennas, the antenna emitting a radio wave. The radome is made of a material allowing passage of the radio wave emitted by the antenna portion, and is disposed to face the antenna surface. The housing forms, together with the radome, a space for accommodating the antenna portion. The housing includes a peripheral edge which surrounds the antenna surface and is in contact with the radome, at least part of the peripheral edge includes a barrier part which protrudes outward from the radome along the antenna surface.