FUEL CELL SYSTEM

The invention relates to a fuel cell system comprising a fuel cell stack () received in a first housing () and an energy supply unit received in a second housing (), the two housings () being connected or being capable of being connected in such a manner that openings () provided in the housings () are opposite one another and overlap, at least in part. According to the invention, an insert (), which surrounds a pin or sleeve-shaped contact element () is arranged in the area of two opposing and at least in part overlapping openings (), wherein the insert () directly, or indirectly via a sealing ring (), encloses the contact element () in a watertight manner and isolates same electrically at least against one of the two housings ().