A friction clutch device includes clutch plates which are retained through meshing engagement on the inner peripheral surface of an outer case, which is rotatably driven by an engine. Each clutch plate includes a flat, annular pressing element which is pressed against a clutch friction plate for frictional contact therewith. Engagement protrusions are formed on the outer peripheral surface of the pressing element. The engagement protrusions fit into recessed engagement grooves provided on the outer case and mesh with the outer case. Proiectinq portions which project toward the inner peripheral surface of the outer case are formed on the outer peripheral surface of the pressing element.