A differential amplifier circuit includes a first differential transistor pair, a second differential transistor pair, an adder section and an amplifying unit. The first differential transistor pair receives first and second input signals and an output signal as a third input signal, and the second differential transistor pair receives the first and second input signals and the output signal as a fourth input signal. The adder section adds first output signals from the first differential transistor pair and second output signals from the second differential transistor pair, and the amplifying unit amplifies an addition resultant signal from the adder section to output to the first and second differential transistor pairs.