Abstract: A sealing system for large-surface thin parts to be interconnected, used for the mutual sealing of separating plates, in particular of bipolar plates with interposed ion-exchange membrane units (MEA) in fuel cells. The system uses sealing elements made of polymer material, in which the individual sealing elements, injected into recesses, form an integral unit with the respective associated bipolar plate. Provision is made between the side walls of the sealing elements and the adjacent walls of the recesses for free spaces or gaps to accommodate the elastic sealing material which spreads during the compression. The sealing elements only partially fill the recesses or gaps and the height (H) of the sealing elements are greater than the depth (T) of the recess or gaps before the compression.