<p>In an antenna for communicating an electromagnetic wave, a first converger converges the electromagnetic wave. A second converger faces the first converger and includes a conductor plate having a through hole, into which a magnetic flux of the converged electromagnetic wave is converged. The through hole is formed at a center portion of the conductor plate so as to have a size which is sufficiently smaller than a wavelength of the electromagnetic wave. The conductor plate is formed with a cutout extending from a part of the through hole to an outer periphery of the conductor plate. A converter faces the through hole of the conductor plate to convert the converged magnetic flux into voltage. <IMAGE> <IMAGE></p>