PURPOSE: To keep the stable receiving state by providing the 1st antenna group of the directivity diversity system and the 2nd antenna group of the space diversity system so as to switch the directivity diversity system or the space diversity system in response to an angle between a vehicle progressing direction and the direction of a broadcast station.

CONSTITUTION: A switch 2 branching a received radio wave by a directivity antenna 1 is normally being selected, a detector 4 detects the level of the reception signal, a microcomputer 5 monitors the level so as to select a maximum reception level and to control a switch 3, thereby extracting the maximum reception level. The space diversity system consists of two omnidirectional antenna 7 and a receiver 6 and a comparator 14 and a switch 15 select the reception level which is higher in the selected levels. A microcomputer 8 collects the information of a broadcast station selected by the receiver 6, the information of a navigation system 9 and information in a memory 10 to detect a radio wave incoming direction and a vehicle progressing direction (road angle θ) and selects a switch 16 in response to the angle θ, thereby selecting the final reception signal. By this constitution, the optimum diversity reception system is selected and stable reception is realized.