NOVELTY - The humidification device comprises a stack (52) of repeating components. The stack comprises a steam-permeable membrane (54), a first layer arrangement (56) arranged on a first side of the membrane, and a second layer arrangement (58) arranged on a second side of the membrane. The first layer arrangement comprises a first flow layer for conducting a process gas to be humidified and a multiplicity of flow channels running parallel to the membrane. The second layer arrangement comprises a second flow layer (66) for conducting a humidified gas.    USE - The device is useful for humidifying process gases in fuel cells (claimed), where the fuel cell is useful in motor vehicles.    ADVANTAGE - The humidification device humidifies a membrane of the fuel cell so that drying of the membrane can be prevented, and ensures high moisture transmission rate of the process gas to be humidified with relatively low space requirement.    DETAILED DESCRIPTION - The humidification device comprises a stack (52) of repeating components. The stack comprises a steam-permeable membrane (54), a first layer arrangement (56) arranged on a first side of the membrane, and a second layer arrangement (58) arranged on a second side of the membrane. The first layer arrangement comprises a first flow layer for conducting a process gas to be humidified and a multiplicity of flow channels running parallel to the membrane. The second layer arrangement comprises a second flow layer (66) for conducting a humidified gas, flow channels running parallel to the membrane and two protective films, which adjoin the second flow layer on both sides and have through-openings. The protective films have active region having a free surface of 55-65%. The through-openings have a circular-shaped form with diameters of 400 mu m. The first layer arrangement further comprises, on both sides of the first fluid layer, spacer films, which have a circumferential frame portion and a circumferential frame area having openings. The protective films and/or the spacer films have a thickness of 40-60 mu m. The flow channels of the first and second fluid layers are opposite to each other in directions. The flow channels of the first and/or second flow layer are open on both sides, and are formed by spaced apart webs. The components of the first layer arrangement and/or the components of the second layer arrangement are connected to one other using an adhesive layer. The stack of the components is arranged in a housing, which is adapted to connect the first fluid layer to a process gas feed line of a fuel cell and the second fluid layers to an exhaust gas discharge line of the fuel cell. An INDEPENDENT CLAIM is included for a fuel cell assembly.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a humidification device.    Stack of repeating components (52)    Steam-permeable membrane (54)    First layer arrangement (56)    Second layer arrangement (58)    Second flow layer. (66)