A cutting device, particularly a lawn mower, has at least one rotating knife mounted on a rotating, motor-driven knife carrier by a screwless, detachable connection. This connection is detachable by a relative rotation between the knife and the knife carrier. It is essential that the connection between the knife and its knife carrier be made by a centrally arranged bayonet lock and that this bayonet lock be locked in the closed position by an additional locking element.