A head lamp apparatus may control a supply of power to a laser diode based on a quantity of white light outputted to an outside environment in the head lamp apparatus using the laser diode as a light source, and controls a power supply using only a quantity of pure white light excluding noise light when the supply of power to the laser diode is controlled, thus maximally preventing blue laser beams, which are harmful to human bodies, from being exposed to the outside environment, and allowing an operation of a head lamp to be precisely controlled.