NOVELTY - In a polymer electrolyte fuel cell gas distributor with a hydrophobized, laminated carbon carrier with 2 surfaces, one with a contact layer of an intimate mixture of 40-90 wt.% finely-divided carbon particles and hydrophobic polyethylene, polypropylene and/or polytetrafluoroethylene, hydrophobization comprises only 2 hydrophobic polymer layers, which extend to a depth of 5-40 microns from both surfaces and fill 20-60% of the carrier pore volume in this region.    USE - The products are gas distributors and gas diffusion electrodes and membrane electrode units containing these for polymer electrolyte fuel cells (all claimed).    ADVANTAGE - Existing gas diffusion electrodes have only a small fraction of open pore volume in the carrier layer. This leads to low capacity when operating with diluted gases, e.g. air and reformate gas, especially at low stoichiometry, i.e. high gas utilization. Also, metal mesh structures are subject to corrosion under the operating conditions of polymer electrolyte fuel cells. The present 4-layer structure avoids these drawbacks. It gives good access of reactive gas to the catalytically active centers of the membrane electrode unit and effective moistening of the ionomer in the catalyst layer and membrane. It also avoids problems in the transport from the cathode side of water formed as reaction product.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (a) gas diffusion electrodes for fuel cells, comprising the gas distributor structure and an electrolyte layer on the contact layer;    (b) membrane electrode units for fuel cells comprising a polymer electrolyte membrane and gas diffusion electrodes on both sides; at least one of which is the cited gas diffusion electrode;    (c) polymer electrolyte fuel cells with the specified membrane electrode unit; and    (d) three methods of producing the gas distributor structure.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the gas distributor structure.    Coarsely porous carbon sheet (1)    Hydrophobic layer (2)    Contact layer (3)