Abstract: A fuel cell stack assembly includes a fuel cell stack, a first pressure-supporting end plate assembly, a first current collector plate, a second pressure-supporting end plate assembly, a second current collector plate, and a pressure-applying structure. The first pressure-supporting end plate assembly is coupled to a first electrode side of the fuel cell stack through the first end plate and the first current collector plate, and the second pressure-supporting end plate assembly is coupled to a second electrode side of the fuel cell stack through the second end plate and the second current collector plate. The pressure-applying structure includes a pressure-applying plate and a pair of side plates form therebetween an open end.