Developing device and image forming apparatus including the same

A developing device (4) for feeding a developer stored therein to an image carrier (2) of the present invention includes a sleeve (4A) facing the image carrier for causing the developer deposited thereon to contact a latent image formed on the image carrier. A regulating member (10) faces the sleeve for regulating the thickness of the developer that forms a layer on the sleeve. A guide member (10A) has a guide surface for guiding the developer regulated by the regulating member toward the surface of the image carrier. The guide surface has a conductive surface facing the sleeve. The developing device protects the image carrier from defective images ascribable to impurities, which include deteriorated toner and paper dust, without resorting to a filter mechanism or a bias for collection.