Abstract: The response characteristics of an output signal and current consumption are kept constant. A drive circuit for outputting an output signal having a voltage determined by a logic of an input signal includes a constant voltage generating section generating a constant bias voltage, a CML circuit outputting the output signal having the voltage determined by the logic of the input signal, where an amplitude of the output signal is determined by a constant current flowing through the CML circuit and a potential of the output signal is determined by the bias voltage, an adjustment constant current source that allows a constant current to flow out from a bias voltage output end of the constant voltage generating section, and a current setting section that sets in advance the constant current flowing into the adjustment constant current source, according to the constant current flowing through the CML circuit.