NOVELTY - The system (1) has a fuel cell (2) comprising a cathode chamber (5) and an anode chamber (3), and a burner (14) i.e. catalytic burner, for afterburning cathode and anode exhaust gases. A turbine (11) produces power from the burned gases and is formed as a part of an electrical turbo supercharger, and a water separator (15) is arranged in a duct element (10) that supplies the cathode exhaust gas between the cathode chamber and the burner, where the anode exhaust gas is supplied into the cathode exhaust gas in front of the separator in a flow direction. The separator comprises a fitting.    USE - Fuel cell system i.e. PEM fuel cell system, for producing electrical power in a partial electrically driven vehicle (all claimed) e.g. partial electrically driven land vehicle, partial electrically driven water vehicle and partial electrically driven air vehicle, that is utilized for transportation purposes. Can also be used for a stationary application.    ADVANTAGE - The water separator is arranged in the duct element, where the anode exhaust gas is supplied into the cathode exhaust gas in front of the separator in the flow direction, so that residual water substance in the anode exhaust gas is mixed with residue oxygen in the cathode exhaust gas in a better manner without utilizing an elongated duct element, thus enabling complete burning of the anode and cathode exhaust gases, and hence ensuring high energy output in the system while preventing hydrogen emissions into environment. The water separator separates the water from the cathode exhaust gas and the anode exhaust gas, so that arrival of the water into regions of the burner and the turbine is avoided, thus protecting the turbine against damages in an efficient manner. The system has a simple and compact structure and is operated in a reliable manner.    DETAILED DESCRIPTION - The fitting comprises guide plates, lattices, knitted fabric and/ filling, and the fuel cell is designed as a proton exchange membrane (PEM) fuel cell.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a fuel cell system.    Fuel cell system (1)    Fuel cell (2)    Anode chamber (3)    Cathode chamber (5)    Duct element (10)    Turbine (11)    Burner (14)    Water separator (15)