To provide an on-vehicle antenna with which antenna characteristics are not degraded by fixing the antenna to the car body.

A male screw part 10a projected on the lower surface of a metal base 10 for antenna is inserted into a hole 26a opened in a car body 26, the metal base 10 for antenna is fixed on the car body 26 by screwing a nut member 30 from the rear side of the car body 26, and a ground connection is performed in electric conducting state. Besides, a waterproofing member 32 composed of a conductive rubber having elasticity and conductivity is interposed between the metal base 10 for antenna and the car body 26.