Provided is an apparatus for changing Media Access Control (MAC) address, which is a conventional subscriber hardware identification address for identifying each subscriber, and a method thereof. The MAC address changing apparatus includes a frame receiving block for determining whether to change a source MAC address; a switch controlling block for controlling a switch; a change MAC address generating block for changing the source MAC address of the received frame; a change MAC address storing block for storing information of the change MAC address and the source MAC address corresponding thereto; a MAC address forwarding and lookup block for extracting output port information; a MAC address replacing block for forming an output frame by replacing the source MAC address; a MAC address storing block for storing a MAC address; and a frame transmitting block for transmitting the output frame.