A phase shifter is disclosed and includes a first substrate comprising a phase change line; and a second substrate comprising an input line connected to an input port, a first output line connected to a first output port, a second output line connected to a second output port, and a connection line connecting the first output line and the second output line. The first substrate is disposed to face the second substrate and to be overlaid at a predetermined distance from the second substrate. A phase of a signal passing through a first portion of the phase change line changes by a first value according to a movement of the first substrate. The signal is branched into a first signal to be transmitted to the first output port and a second signal to be transmitted to the second output port.