A packet processing apparatus and method are provided. The packet processing apparatus changes a size of an input packet, analyzes the input packet to perform a second layer associated process, generates basic delivery headers of the input packet, processes the input packet to which the basic delivery headers are inserted according to a type of the input packet, transforms the header of the input packet to which the basic delivery headers are inserted, and transitions the header-transformed input packet to delivers the packet. Accordingly, it is possible to process various packets without addition of separate process to the packet processing apparatus. In addition, a use efficiency of a network processing unit can be optimized, so that it is possible to increase a packet processing rate and performance.