The present invention relates to a camera module having an auto focus function, the module including a lens unit having at least one lens, a barrel into which the lens unit is inserted, and connected by a VCM (Voice Coil Motor) actuator, and an image sensor discretely positioned from the lens unit to convert light having passed the lens unit to an electrical signal, where the VCM actuator includes a gap of a reference distance position value which is a position of an object catering to a lens focal length according to the camera module, and information on a focus-met lens position value, and adjusts an initial position of the lens by using the gap of reference distance position value of the lens position value during operation of the camera module.