NOVELTY - The method for operating a high-temperature fuel cell (1), comprises supplying the fuel cell with liquid fuel (B) such as diesel, in a normal mode for generating power, where the fuel cell has a reformer (2) for the liquid fuel connected upstream at the anode end. A portion of the hot anode exhaust gas is returned to the anode circuit via a return line (3), where the liquid fuel is sprayed or injected into the hot anode exhaust gas upstream of a compressor (4), which is connected upstream of the reformer.    USE - Method useful for operating a high-temperature fuel cell.    ADVANTAGE - The method ensures efficient and simple operation of a high-temperature fuel cell.    DETAILED DESCRIPTION - The method for operating a high-temperature fuel cell (1), comprises supplying the fuel cell with liquid fuel (B) such as diesel, in a normal mode for generating power, where the fuel cell has a reformer (2) for the liquid fuel connected upstream at the anode end. A portion of the hot anode exhaust gas is returned to the anode circuit via a return line (3), where the liquid fuel is sprayed or injected into the hot anode exhaust gas upstream of a compressor (4), which is connected upstream of the reformer. The quantity of air required for reforming the liquid fuel is added to the mixture comprising anode exhaust gas and fuel. The supply of liquid fuel and air is stopped and the gas mixture located in the anode circuit is permanently circulated when a changeover is made from the normal mode to a standby mode without power generation. A defined quantity of air is supplied to the anode circuit in order to remove deposits and impurities from the high-temperature fuel cell starting from the standby mode. The supplied air quantity is measured in such a way that an oxygen content of 0.5-10 vol.% adjusts itself in the anode circulation after the oxidation of the fuel components present itself in circulation. An exhaust gas-recirculation rate of 100% is adjusted in standby mode operation during switching off. The anode circuit is locked during the standby mode operation in order to prevent the suction of medium such as environment air.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic representation of an operation mode of a method for operating a high-temperature fuel cell.    Fuel cell (1)    Reformer (2)    Return line (3)    Compressor (4)    Liquid fuel. (B)