To eliminate causes to malfunctions by selecting a switching speed to be low by relieving processing load in the case of measuring the reception quality of antennas so as to reduce the number of antenna switching times at the measurement and to suppress reduction in the throughput of user data in the case of antenna control.

The antenna controller is provided with a sector antenna section 101 that has sectors #1-#6 having directivity in sartorial angular directions, a control means 104 allows a sector switch section 102 to sequentially select an antenna element used for transmission/reception and other optional antenna elements than this antenna element, a reception level is measured at a preamble part of the signal received by the selected antenna elements and the control means 104 allows the sector switch section 102 to select the antenna element receiving the signal with the highest measured level.