Various embodiment(s) for a service system, a digital device, and a method of processing a service therefor are disclosed in the present specification. In this case, according to one embodiment of the present invention, a method of processing a service in the digital device includes the steps of downloading and installing one or more STB applications configured to process the service, outputting an icon configured to approach the installed STB applications on a first service board supporting an RF mode, receiving a selection of an STB application icon among the STB applications, and outputting content processed by the selected STB application according to a result of a service authentication and a second service board for the selected STB application.