A development device includes a developer carrier, a blade and a cover. The developer carrier carries a developer containing a toner. The blade regulates a thickness of the developer carried on the developer carrier. The cover includes a cover main body covering an outer side of the blade and a facing rib protruding from an inner face of the cover main body and facing the developer carrier at an interval. A storage space to store the toner which contacts the facing rib and falls is formed below the facing rib.