The present invention discloses a home network system (1) using a living network control protocol. The home network system (1) includes: at least two electric devices (41-49); and a network based on a predetermined protocol for connecting the electric devices (41-49), wherein a message transmitted between one electric device (41-49) and the other electric device (41-49) includes a command code field implying an operation that is to be performed by the other electric device (41-49), and an argument field according to a version of a protocol applied to one electric device (41-49) for performing the operation.