9 for rotating the rotary member 7 about the azimuth angle axis and 10 a gear provided on the rotary shaft of the motor 9 and engaging with a gear formed at an outer periphery of the rotary member 7 reference numeral 11 designates an antenna driven at a predetermined angle in the azimuth angle and the elevation angle and carrying out wireless communication with an opposite communication station reference numeral 12 designates an elevation angle rotary shaft provided on the antenna 11 and 13 a supporting leg for supporting the elevation angle rotary shaft 12 the antenna 11 is provided on the rotary member 3 rotatably in the elevation angle direction through the support leg 13 reference numeral 14 designates a relative rotary shaft rotating by relative rotation between the rotary member 3 and the rotary member 7 and 15 a bearing for rotatably supporting the relative rotary shaft 14 with respect to the rotary member 3 this bearing 15 is fitted into a hole formed in the rotary member 3 reference numeral 16 designates a gear provided at one end of the relative rotary shaft and engaging with gear teeth 17 provided on the rotary member 7 shown in fig2 the gear teeth 17 are gear teeth provided on the periphery around the rotary shaft of the rotary member 7.