A phase shifter comprising: a first all-pass filter including a plurality of elements; a second all-pass filter including a plurality of elements; a first switching switch to provide a signal to either one of the first all-pass filter and the second all-pass filter; and a second switching switch to select the signal having passed through the first all-pass filter or the signal having passed through the second all-pass filter, wherein the first all-pass filter includes a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor as the plurality of elements, the second all-pass filter includes a third inductor, a fourth inductor, a fourth capacitor, a fifth capacitor, and a sixth capacitor as the plurality of elements, the first inductor is inserted in a first path that connects the first switching switch to the second switching switch, a first end of the first capacitor is connected to a first end of the first inductor, a first end of the second capacitor is connected to a second end of the first inductor, a first end of the second inductor is connected to a second end of each of the first capacitor and the second capacitor, a first end of the third capacitor is connected to a second end of the second inductor, and a second end of the third capacitor is grounded, the third inductor is inserted in a second path that connects the first switching switch to the second switching switch, a first end of the fourth capacitor is connected to a first end of the third inductor, a first end of the fifth capacitor is connected to a second end of the third inductor, a first end of the fourth inductor is connected to a second end of each of the fourth capacitor and the fifth capacitor, a first end of the sixth capacitor is connected to a second end of the fourth inductor, and a second end of the sixth capacitor is grounded and values of the plurality of capacitors and inductors included in the first and second all-pass filters are determined such that impedance matching is achieved in a desired frequency band. a first all-pass filter including a plurality of elements; a second all-pass filter including a plurality of elements; a first switching switch to provide a signal to either one of the first all-pass filter and the second all-pass filter; and a second switching switch to select the signal having passed through the first all-pass filter or the signal having passed through the second all-pass filter, wherein the first all-pass filter includes a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor as the plurality of elements, the second all-pass filter includes a third inductor, a fourth inductor, a fourth capacitor, a fifth capacitor, and a sixth capacitor as the plurality of elements, the first inductor is inserted in a first path that connects the first switching switch to the second switching switch, a first end of the first capacitor is connected to a first end of the first inductor, a first end of the second capacitor is connected to a second end of the first inductor, a first end of the second inductor is connected to a second end of each of the first capacitor and the second capacitor, a first end of the third capacitor is connected to a second end of the second inductor, and a second end of the third capacitor is grounded, the third inductor is inserted in a second path that connects the first switching switch to the second switching switch, a first end of the fourth capacitor is connected to a first end of the third inductor, a first end of the fifth capacitor is connected to a second end of the third inductor, a first end of the fourth inductor is connected to a second end of each of the fourth capacitor and the fifth capacitor, a first end of the sixth capacitor is connected to a second end of the fourth inductor, and a second end of the sixth capacitor is grounded and values of the plurality of capacitors and inductors included in the first and second all-pass filters are determined such that impedance matching is achieved in a desired frequency band.