There is provided an amplifier circuit. The amplifier circuit includes an amplifying unit including at least one transistor; at least one first bias circuit unit including a resistor and connected to the at least one transistor; and at least one second bias circuit unit connected between an input terminal to which an input signal is applied and the at least one transistor so as to block an input signal having a frequency higher than a first frequency or having a frequency lower than a second frequency. The amplifier circuit according to embodiment of the present invention may prevent thermal runaway, remove a harmonic component from an input signal to be amplified and suppress oscillations.