PURPOSE: To unnecessitate forbidden bands over a wide range and to reduce erroneous communication by arranging the opening face of a first loop antenna while facing it to the opening face of a second loop antenna.

CONSTITUTION: A transmitted signal from a transmitter/receiver 1 is impressed to loop antenna parts 2 and 3 with the same phase. At such a time, the loop antenna parts 2 and 3 are provided with 8-shaped directivity and the transmitting current of the loop antenna part 2 is provided with the same phase as the transmitting current of the loop antenna part 3 so that the electric field component and magnetic field component of an electromagnetic wave transmitted from the loop antenna part 2 can be provided with the same phase of the electric field component and magnetic field component of an electromagnetic wave transmitted from the loop antenna part 3. As a result, the electric field component and magnetic field component of the electromagnetic wave to be generated are overlapped each other, and a communication area becomes a pillar-shaped area. At such a time, the characteristics of the loop antenna parts 2 and 3 are synthesized inside this area, and the electric field component and magnetic field component of the electromagnetic wave are made stronger in comparison with the peripheral parts. In the case of receiving the electromagnetic wave, reception sensitivity is made higher in comparison with the periphery as well.