NOVELTY - The device (1) has a fuel tank (2) for fuel, and a fuel cell (14) provided with a cathode (16) and an anode (18). A reactor (4) is provided for reforming fuel from the fuel tank into the hydrogenous fuel gas. The reactor comprises a fuel gas outlet (5) that is connected to fuel gas inlet (13) arranged on the anode of the fuel cell. An inert gas outlet (21) is arranged downstream of the reactor, to form a fluid sink for non-hydrogenous reaction products of the reactor.    USE - Device for producing inert gas, used in airplane (claimed).    ADVANTAGE - The inert gas is produced by membrane separation modules associated with consistent consumption of power for maintaining required high pressure difference at the membrane. The largely dry inert gas is produced with low power demand. The compressed air i.e. air with a pressure that lies above the ambient pressure is fed to the cathode to minimize pressure losses within the fuel cell, as well as to ensure uniform gas distribution on the electrodes of the fuel cell, and to maintain the volume flow through the fuel cell as low as possible. The inert gas outlet is connected to residual gas outlet of the gas separation unit, to provide a nearly pure inert gas at the inert gas outlet, so that inert gas does not contain any hydrogen if the fuel cell process is not performed ideally. The combustible hydrogen reaching the fuel tank during inerting can be prevented, even if the hydrogen is not used completely in the fuel cell process. Since the fuel cell generates electricity during the production of inert gas, the compressor can be directly driven by the fuel cell, and the device is enabled to make the inert gas available in an autarkic fashion. The additional weight of the device can be partially compensated with corresponding dimensioning of the relieved power sources such as generators in thrusters. The blind loads that ensure a continuous current flow to the voltage output of fuel cell can be provided.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for method for providing inert gas.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the device for producing inert gas. (Drawing includes non-English language text)    Device for producing inert gas (1)    Fuel tank (2)    Reactor (4)    Fuel gas outlet (5)    Fuel gas inlet (13)    Fuel cell (14)    Cathode (16)    Anode (18)    Inert gas outlet (21)