Fuel cell with flat assembly and simplified sealing

Flat fuel cell comprising at least two unit cells juxtaposed in one plane, a casing provided with supports for each unit cell, each support offering a bearing surface at a periphery of an unit cell, said fuel cell also comprising sealing means interposed between the periphery of each unit cell and the surface of its support, and a compression element, associated with each support, coming into abutment on the periphery of the unit cell opposite to the sealing means and cooperating directly with the associated support in order to provide compression of the sealing means, said casing delimiting a reactant supply chamber, a first electrode of each of the unit cells being in contact with the internal volume of the supply chamber, a second electrode of each unit cell being oriented towards the outside of the casing, said compression of the sealing means providing a seal for the supply chamber vis-á-vis the outside of the casing.