The invention relates to a polar plate assembly for a fuel cell, comprising: a polar plate which comprises, on at least one of its flat sides, elevations and free spaces arranged between them, which form a flow structure for a reactant; and a supporting structure designed to prevent or at least reduce an intrusion by a gas diffusion layer adjacent to the supporting structure and/or a membrane electrode assembly into the free spaces of the flow structure. It is provided that the polar plate assembly is designed such that the polar plate protrudes into the supporting structure. The invention furthermore relates to an individual cell with a polar plate assembly according to the invention.