A multimedia service apparatus and method for multimedia service providers outside home to UPnP devices inside home using a home gateway and a service gateway platform is provided. In the multimedia service apparatus and method, the home gateway and the service gateway platform such as an open service gateway initiative (OSGi) service platform are used inside a home so that the multimedia service providers outside home can provide a multimedia content on a home network to a universal plug and play (UPnP) audio/video (AV) MediaRenderer following a UPnP AV structure based on UPnP, to reproduce or store the multimedia content in a UPnP AV MediaServer. The multimedia service apparatus includes: a UPnP AV (audio/video) device connected to a home network by the multimedia service provider of an external network; and a gateway device providing a multimedia service to the UPnP AV device using the service gateway platform.