A plurality of plane antennas 6-1 and 6-2 are embedded in the equipment body section 1, and every time occurrence of reception failure is detected by the internal electronics circuit, switching between the antennas used is established. Spatial diversity through selectively switching and using the plurality of plane antennas 6-1 and 6-2 is performed. Through this, even when reception sensitivity of one antenna in use deteriorates, good reception sensitivity can be gained through switching to another antenna. Thus, this can avoid inconvenience where calls are cut off.