Abstract: The invention herein relates to a PEM fuel cell stack consisting of one or more superimposed fuel cells (1), each containing a membrane electrode assembly (2) and electrically conductive bipolar plates (3, 4), whereby the membrane electrode assemblies each comprise a polymer electrolyte membrane (5), which is in contact on each side with a reaction layer (6, 7); whereby the reaction layers cover a smaller area than the polymer electrolyte membrane, and between each reaction layer and the adjacent bipolar plates—essentially congruent with the reaction layers—respectively one compressible gas distribution layer (8, 9) of carbon fiber material is provided, and gaskets (11, 12) are interposed in the region outside the area covered by the gas distribution layers; whereby the gas diffusion electrodes formed by the reaction layers and the gas distribution layers exhibit a no-load thickness of D1 and the gaskets a thickness D2.