A developing apparatus is disclosed that employs one-component non-magnetic toner. The apparatus includes a movable developing agent carrier that has a surface polished to a first finish, roughened to a second finish, and then metal plated. The agent carried carries a one-component developing agent composed of non-magnetic toner and supplies the developing agent to an electrostatic latent image. An elastic coating member is disposed to press on the surface of the movable developing agent carrier so that the free end thereof is directed opposite to the moving direction of the movable developing agent carrier, and a toner stirring member disposed in a toner container contiguously to or in sliding contact with the movable developing agent carrier. The apparatus provides a uniform toner layer over a long period of time and supplies stable and high quality images.