A high-frequency switch circuit is provided for switching a connection between a common transmission circuit and antenna side circuit in a plurality of transmitting and receiving systems. The high-frequency switch includes a connection between the antenna side circuit and a reception circuit in one of the plurality of transmitting and receiving systems, and a connection between the antenna side circuit and a reception circuit in the other of the plurality of transmitting and receiving systems, the high-frequency switch circuit comprising a first diode; a first distributed constant line; a second diode; a capacitor; a third diode; a second distributed constant line; and a fourth diode.