NOVELTY - The seal has a rectangular central opening coinciding with a central rectangular surface of a bipolar plate (22) so that a distribution channel of the surface of the plate is not covered by the seal during the fixation of the seal on the plate. The seal is in the form of a membrane and has a section corresponding to a peripheral frame of a bipolar plate. The seal has a front face (76) on which a peripheral frame (75) of an electrode membrane assembly (70) of a fuel cell is supported so that an active region (74) of the assembly and the coolant inlet and outlet windows are sealed.    USE - Fuel cell seal e.g. flat seal and seriographic seal, for being affixed on a bipolar plate of a fuel cell (claimed) e.g. proton exchange membrane fuel cell, that is utilized for converting chemical energy into electric energy from a fuel e.g. hydrogen and a fuel oxidizer e.g. oxygen and air containing oxygen, where the electrical energy is provided to a device e.g. computer, portable telephone, and for ensuring the traction of a motor vehicle and/or the supply of electrical devices contained in the vehicle.    ADVANTAGE - The seal, in the form of a membrane, has a section corresponding to the peripheral frame of the bipolar plate, thus ensuring better sealing without crushing the seal. The peripheral frame of the electrode membrane assembly is supported on the front face of the seal, without excessive deformation, thus ensuring the sealing of the active region of the assembly and the coolant inlet and outlet windows and the sealing between the active region of the assembly and the exterior of the cell without the risk of shearing the peripheral frame.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a fuel cell comprising an electrode membrane assembly sandwiched between bipolar plates on which a seal is affixed.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of an upper part of a bipolar plate comprising a fuel cell seal.    Bipolar plate (22)    Electrode membrane assembly (70)    Active region (74)    Peripheral frame (75)    Seal`s front face (76)