An RF switch is provided. In the RF switch, a T-junction slot line has a horizontal slot line and a vertical slot line. An open-end circuit is provided at each end portion of the horizontal and vertical slot lines. A first transmission line delivers signals from and to one portion of the horizontal slot line, and a second transmission line delivers signals from and to the other portion of the horizontal slot line. A third transmission line delivers signals from and to the vertical slot line. A switching circuit selectively switches the signal path of the one or the other portion of the horizontal slot line to the vertical slot line according to an external switching control signal.