PURPOSE: To obtain a compact and lightweight switching device for plane of polarization by connecting a 1st and a 2nd switches of a four-port switch to an antenna and a transmitter or a receiver respectively and providing a specific operating means for plane of polarization between the 1st and 2nd switches.

CONSTITUTION: The 1st and 2nd four-port switches S5 and S6 are connected to an antenna 3 and a transmitter or receiver 2 respectively. An operating means for plane of polarization is set between both switches S5 and S6 and distributes the high frequency electric power to two transmission lines L5 and L6 to operate the phase of said electric power of the line L5 or to synthesize the electric powers of both lines L5 and L6 after operation of the phase of the line L5. Then it is possible to select a vertical polarized wave, a horizontal polarized wave or a right/left polarized wave according to combinations of switching positions of both switches S5 and S6.