The first Meteosat Second Generation (MSG) satellite has been launched in August 2002. This EUMETSAT's satellite carries 2 new instruments on the geostationary orbit: the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) and the Geostationary Earth Radiation Budget (GERB). The unique feature of GERB in comparison with previous measurements of the Earth's radiation budget (e.g. ERBE, ScaRaB and CERES experiments) is the high temporal sampling afforded by the geostationary orbit, albeit for a limited region of the globe. The GERB instrument provides accurate broadband measurements of the radiant energy due to the reflection of the incoming solar energy by the Earth-atmosphere system and due to the thermal emission within this system. The synergetic use of the SEVIRI data is needed to convert these directional measurements (radiances) into radiative fluxes at the top-of-atmosphere. Additionally, the SEVIRI data allows the enhancement of the spatial resolution of the GERB measurement. The first part of the RMIB contribution describes the near real-time GERB processing system that has been set up at the Royal Meteorological Institute of Belgium (RMIB). This includes the unfiltering of the instrument data, the radiance-to-flux conversions and the spatial resolution enhancement.