Fuel cell device with several cascade steps

The device (1) has cascade layers (2-5) flowed-through by operating gas and comprising fuel cells (10) i.e. polymer electrolyte membrane-fuel cells. The cells have gas distribution structures, and a gas supply (8) is guided from one of cascade layers to another cascade layer. A filter (15) is arranged in the gas supply and provided for separating released components of the structures from the gas, where the filter is made from stainless steel. A water separator (14) is arranged in the gas supply, and the filter is arranged in a flow direction of the operating gas after the water separator.