Abstract: A fuel cell stack comprises several mutually stacked fuel cells, each of which has a cathode-electrolyte-anode unit, and a perforated foil for distributing a fuel gas over a first electrode surface. The foil carries the cathode-electrolyte-anode unit and is assembled with a further structure to form an enclosure having a cavity through which fuel gas flows to the first electrode. Opposite the cathode-electrolyte-anode unit, each enclosure has a distribution configuration for distributing air-oxygen over the surface of the second electrode of an adjacent enclosure, so that a cathode-electrolyte-anode unit and a distribution configuration are situated between the foil and the further structure of adjacent enclosures in the stack. In addition, the stack contains at least one bracing enclosure whose walls have an impermeable construction and which is filled with a material expands when heated.