PURPOSE: To obtain a stable and high voltage gain with small configuration and low power consumption with respect to an input signal with a comparatively high frequency by using a differential pair transistors(TRs) so as to apply positive feedback to an input stage differential amplifier section.

CONSTITUTION: The differential amplifier is provided with an input stage differential amplifier section 1 receiving an input signal, amplifying the signal and obtaining an output signal and a differential feedback circuit section 2 applying positive feedback to the input stage differential amplifier section 1. Since positive feedback is applied from the differential feedback circuit section 2 with simple configuration to the input stage differential amplifier section 1 in this way, even when the resistance of load resistors R1, R2 in the input stage differential amplifier section 1 is set small, a high voltage gain is obtained without increasing a bypass current.