FUEL CELL STACK

A fuel cell stack FS includes: a stack A that includes a single cells C that are stacked, each of the single cells including a frame that holds an outer periphery of a membrane electrode assembly and a pair of separators sandwiching the membrane electrode assembly and the frame and a case that houses the stack A. The frame comprises a protrusion that protrudes outward from an outer periphery of a frame body A beyond an outer peripheral edge of the pair of separators A protrusion length of the protrusion is greater than at least a gap between the frame and one of the pair of separators and the protrusion is bendable with respect to the frame body A. The protrusions prevent a contact between the separators of the single cell C and a contact between the end faces of the separators and the case so as to prevent a short circuit of the single cell C.