Embodiment(s) for a service system, a digital device and a method of processing service thereof are disclosed in the present disclosure. In this case, according to one embodiment, a digital device of processing ultra-high definition (UHD) video data includes a receiving unit configured to receive a first signal containing first UHD video data and signaling data for the first UHD video data, a decoder configured to decode the signaling data from the first signal, a user interface unit configured to receive a second signal requesting for converting the first UHD video data to second UHD video data through a remote controller, a controller configured to control a converter to convert the first UHD data to the second UHD data in response to the received second signal, the converter and a display configured to display the converted second UHD video data on a display screen.