A transmitting and receiving circuit that transmits and receives signals using coaxial cables includes an input/output terminal that delivers and receives signals, a first port, a second port, a switch, and a ceramic-based electro-static discharge protector. The first port transfers a transmitted signal in a first transmission frequency band width and a received signal in a first reception frequency band width. The second port transfers a transmitted signal in a second transmission frequency band width and a received signal in a second reception frequency band width. The switch connects a common port to one of the first port and the second port. The common port is connected to the input/output terminal on one end of the common port and to the switch on the other end. The electro-static discharge protector is connected between the common port and the ground potential.