To prevent reception sensitivity from being lowered by leaking a received signal excited at an antenna through a wiper conductive section by connecting a filter circuit between the wiper conductive section and a car body conductive section and cutting off or attenuating one part or all of the desired broadcasting band frequency through the filter circuit.

An antenna conductor 4 provided at a margin part upper than a defogger 3 of a window glass pane 1 at the rear part of an automobile and a branch line 3a of the defogger 3 are made proximate at a prescribed interval and the antenna conductor 4 and defogger 3 do not exchange a DC current but are coupled in capacitance and exchange a high frequency current. A choke coil 8 and high frequency choke coils 12a and 12b are connected between bus bars 5a and 5b and a DC power source 10 and by enlarging an impedance on a high frequency band, the DC current flows from the DC power source 10 to the defogger 3 but a broadcasting band reception signal current is cut off. Thus, the reception current excited at the defogger 3 is prevented from leaking to a car body and the defogger 3 is insulated from a car body ground in the manner of high frequency.