The present invention provides an inverter circuit with a power factor corrector. A power source provides a power signal of alternating current. An electromagnetic interference filtering unit and a rectifier unit receive the power signal of alternating current, filter and rectify the power signals, and then output a half-wave power signal of direct current. A voltage adjusting unit provides a voltage adjusting value. A power factor corrector receives the half-wave power signal of direct current, connected to the voltage adjusting unit, converting the voltage of the half-wave power signal of direct current in accordance with the voltage adjusting value, and then outputting a power signal. An inverter steps up the voltage and outputting a power signal with high voltage to a load which is subsequently connected to the inverter, such that the power signal with high voltage has preferred corrected power factor and adjusts the brightness of the load.