The present invention provides a novel gate driver apparatus in which an energy recovery circuitry is incorporated in a square-wave gate driver. The energy recovery circuitry comprises a first loop circuit for discharging the energy from the gate capacitor to an inductor when the gate driver is turned off, and a second loop circuit for discharging the energy from the inductor to the power supply. Thus, the energy of the gate capacitor is transferred to the power source when the gate driver is turned off, and the gate driver apparatus still maintains its operating flexibility as the square-wave driver and is independent of switching frequency.