In a transmission device for differential communication, a first cathode-side element part is coupled between a first communication line and a cathode-side power supply line, a second cathode-side element part is coupled between a second communication line and the cathode-side power supply line, a first anode-side element part is coupled between the first communication line and an anode-side power supply line, and a second anode-side element part is coupled between the second communication line and the anode-side power supply line. A driving portion drives the element parts based on transmission data input from an outside. A target potential generating portion generates target potentials of the element parts based on potentials of the first communication line and the second communication line.