Embodiments of the invention provide a power supply apparatus, including an AC/DC rectifying unit converting an AC voltage into a DC voltage, a power factor correction unit correcting a power factor of the DC voltage, and a DC/DC conversion unit converting the DC voltage having the corrected power factor into a DC voltage having a different magnitude therefrom. According to various embodiments, the power supply apparatus further includes an auxiliary winding connected to a primary side winding of a transformer of the DC/DC conversion unit and generating the DC voltage having a predetermined magnitude, and an internal power generation unit connected to an output terminal of the power factor correction unit and the auxiliary winding and using a voltage of the output terminal of the power factor correction unit and a voltage generated by the auxiliary winding to generate temporary Vcc power and supply the generated temporary Vcc power as internal power of the power factor correction unit.