The invention provides a small phase shifter and a small multibit phase shifter, in which a filter including a capacitor formed during pinchoff of a FET is used to shift phases depending on the ON/OFF operation of the FET. The phase shifter comprises a first FET connected at its drain and source electrodes with an input terminal and an output terminal; a second FET connected at either one of its drain and source electrodes with the source of the first FET and grounded at the other through a first inductor; and a third FET connected at either one of its drain and source electrodes with the drain of the first FET and grounded at the other through a second inductor.