A bipolar plate, including conductive sheets, and in which flow channels are made between the conductive sheets and are in communication with a coolant inlet and outlet manifolds. An outer face of a conductive sheet includes first ribs delimiting reactant flow channels, and a second rib extending on the side of the reactant flow channels. A sealing gasket extends at least partially on the second rib. The outer face of the conductive sheet further includes third ribs extending between a first rib and the second rib, between which an alternation of third ribs and of indentation is formed. The sheets are in contact at the level of indentations, and respective passages are formed under the third ribs.