A phase shifter (60) is provided corresponding to an antenna element constituting an array antenna and is configured to change a phase of a radio frequency signal to be transmitted or received by a corresponding antenna element. The phase shifter (60) includes a first distributor (61) configured to distribute the radio frequency signal input thereto into a plurality of first distributed signals having mutually different phases; second distributors (62) provided corresponding to the first distributed signals, the second distributors each being configured to distribute a corresponding one of the first distributed signals into a plurality of second distributed signals having mutually different amplitudes; a controller (63) configured to control on/off of the second distributed signals; and a combiner (64) configured to combine the second distributed signals that are controlled on by the controller (63).