A differential transmission circuit for a communication device performs bidirectional communication via a differential transmission line. The differential transmission circuit include: output transistors that are turned on and off according to a drive signal during a transmission period; a signal generation unit that generates and outputs the drive signal; short-circuit transistors connected between gates and drains of the output transistors; and a cut off unit that cuts off a supply path of the drive signal between the signal generation unit and the gates of the output transistors. The cut off unit cuts off the supply path of the drive signal during a reception period in which a reception operation is performed by the communication device.