PURPOSE: To set up an operation range almost within a power supply voltage range.

CONSTITUTION: This differential amplifier is provided with a pnp differential input stage (Q16, Q17) to be driven by a constant current transistor(TR) Q15 connected to one end of a power supply E, an npn differential input stage (Q18, Q19) connected in parallel with the base of the input stage (Q16, Q17) and driven by a constant current TR Q20 connected to the other end of the power supply E and an adding circuit 5 connected to the collectors of both the input stages (Q16, Q17), (Q18, Q19) and mutually adding and outputting outputs currents from both the input stages (Q16, Q17), (Q18, Q19) in accordance with input voltage impressed to its base.