The present invention provides a fuel cell separator with a gasket manufactured by integrally forming a gasket on one side of a separator; independently injection molding a frame gasket on a frame such that a first airtight portion covers the entire surface of the frame to maintain the shape of the frame gasket and a second airtight portion projects upward and downward from both ends of the first airtight portion; and bringing the first airtight portion of the frame gasket into contact with the other side of the separator with the gasket formed on one side thereof. To create a fuel cell stack in certain embodiments, the invention stacks the second airtight portion of the frame gasket on another second airtight portion of an adjacent unit cell with a membrane-electrode assembly interposed therebetween.