A developing device and an image forming apparatus equipped with the developing device are provided to suppress the deterioration in picture quality of an image formed on a sheet due to toner-clump created in a developer vessel. The developing device includes a developing roller adapted to hold toner thereon while rotating and to supply the toner onto a photosensitive surface of a photosensitive body and a toner recovery vessel adapted to accommodate the developing roller therein with facing an opening portion thereof and to supply the toner to be held on the developing roller onto the developing roller while recovering residual toner remaining on the developing roller. The toner vessel including a protrusion portion protruded toward a roller surface of the developing roller. The protrusion portion is provided at an inner wall part which confronts the roller surface of the developing roller and where the residual toner begins to drop from the developing roller.