To provide an MMIC low noise amplifier capable of reducing a component cost and an assembly cost.

A circuit in which the gate terminal of an FET 1 is grounded through a feedback resistor 8 and a resistor 11 for gate grounding serially connected to it, a drain terminal is grounded through the connection point of the feedback resistor 8 and the resistor 11 for gate grounding and a first capacitor 10 for output matching, the connection point and a signal output terminal are connected through a second capacitor 12 for output matching and a source terminal is grounded through a self bias circuit is monolithically formed. Then, a signal input terminal 4 and the gate terminal of the FET 1 are connected through an input matching circuit 14 and the drain voltage of the FET 1 is supplied through an external inductor 9.