An SPST switch having a small transmission loss and a small power
consumption is provided. The drain and the source of an FET are connected
to each other in series through an induction element and a capacitor
element, one terminal of the capacitor element is connected to a first
terminal, the other terminal is connected to a second terminal, the gate
of the FET is connected to a control terminal, the capacitance of the
capacitor element is made equal to the OFF capacitance of the FET, and the
inductance of the induction element is set to be such a value that the
induction element resonates at a signal frequency with the capacitor
element.