A directional coupler for use in a communication module comprising a switching element , the directional coupler comprising: a signal input terminal (P1) to which an electric signal in a predetermined first frequency band and an electric signal in a predetermined second frequency band higher than the first frequency band are input; a first signal transmission line through which the electric signal input to the signal input terminal is transmitted; a signal output terminal (P2) from which the electric signal transmitted through the first signal transmission line is output; a coupled line which is electromagnetically coupled to the first signal transmission line and through which an electric signal generated by being electromagnetically coupled is transmitted; a coupled output terminal (P3) to which a first end of the coupled line is connected and from which the electric signal transmitted through the coupled line is output; a resistance connection terminal (P4) which is connected to an external terminating resistance (Rt) and to which a second end of the coupled line is connected; characterized in that the directional coupler further comprises a second signal transmission line disposed between the signal input terminal (P1) and the signal output terminal (P2) via the switching element and electrically connected or disconnected by the switching element, the second signal transmission line being electrically connected by the switching element when the electric signal in the first frequency band is input to the signal input terminal, and the second signal transmission line being electrically disconnected by the switching element when the electric signal in the second frequency band is input to the signal input terminal. a signal input terminal (P1) to which an electric signal in a predetermined first frequency band and an electric signal in a predetermined second frequency band higher than the first frequency band are input; a first signal transmission line through which the electric signal input to the signal input terminal is transmitted; a signal output terminal (P2) from which the electric signal transmitted through the first signal transmission line is output; a coupled line which is electromagnetically coupled to the first signal transmission line and through which an electric signal generated by being electromagnetically coupled is transmitted; a coupled output terminal (P3) to which a first end of the coupled line is connected and from which the electric signal transmitted through the coupled line is output; a resistance connection terminal (P4) which is connected to an external terminating resistance (Rt) and to which a second end of the coupled line is connected; characterized in that the directional coupler further comprises a second signal transmission line disposed between the signal input terminal (P1) and the signal output terminal (P2) via the switching element and electrically connected or disconnected by the switching element, the second signal transmission line being electrically connected by the switching element when the electric signal in the first frequency band is input to the signal input terminal, and the second signal transmission line being electrically disconnected by the switching element when the electric signal in the second frequency band is input to the signal input terminal. <EOS>