A differential amplifier circuit of simple circuit configuration is disclosed, which is capable of releasing an output signal within a voltage range independent of the voltage range of a differential input signal. The differential amplifier circuit 1 includes: NMOS transistors N1, N2 that constitute a first differential pair configured to input a differential input voltage; a resistor element Ra connected to drain terminals X1, X2 of the NMOS transistors N1, N2; an op-amp OP having input terminals connected to the drain terminals X1, X2; and NMOS transistors N3, N4 that constitute a second differential pair configured to input an output voltage of the op-amp OP and a reference voltage. The drain terminals of the first differential pair are connected to drain terminals, respectively, of the second differential pair.