To realize a compact and thin type directional antenna with a few elements and a simple circuit constitution.

A plurality of vertical polarization antenna elements having the same center frequency are laid closely on the same board surface, and connected to a transmitter-receiver circuit through an antenna switching circuit which selects one of the antenna elements to act it as a radiator, while other antenna elements not connected to the transmitter-receiver circuit act as reflectors. Selecting the antenna element to be active improves the directivity of the antenna. The center-to-center distance of the antenna elements is set to about 0.2-0.4 wavelength.