To allow the method enough to need a required minimum for the number of installed base stations by automatically rocking an antenna around its base and monitoring a reception state of a radio wave for each prescribed angle, upon receipt of the radio wave from a terminal equipment to stop the rocking at an angular position in a best reception state, thereby extending a radius of a cell.

A control section 5 usually rocks reciprocatingly an antenna 9 via a motor control section 6. In this case, a reception status monitor section 13 always monitors a reception state for each prescribed angle within an antenna locking plane via a radio section 4 and an LSI section 3 and stores data of the reception state to a memory section 12 upon the detection of a reception radio wave from a terminal equipment 1. A reception status discrimination section 15 discriminates an angle offering a best reception state via a comparator section 14 based on the data and an angle decision section 16 decides the angle of an antenna stop position. A stop command generating section 17 stops the rocking of the antenna 9 at a decided angular position. Thus, the directivity of the antenna 9 is utilized at a maximum to extend the radius of a cell.