The present invention discloses an upgrade apparatus and its method for a home network system which can automatically upgrade software. The upgrade apparatus for the home network system is installed in the home network system having a first storage unit in which at least one protected program has been installed, and includes n upgrade means for deciding whether a second storage unit separated from the first storage unit stores an upgrade file corresponding to the protected program, and upgrading the protected program by using the upgrade file according to the decision result.