In an image forming apparatus, a developing device of the type developing an electrostatic latent image formed on an image carrier by using single-component type toner has a regulating member for regulating the amount of the toner fed thereto, a first conveying member for conveying the toner regulated by the regulating member and deposited thereon, and a second conveying member for conveying the toner transferred from the first conveying member thereto to the image carrier. The first and second conveying members are each movable at a particular speed in a particular direction. The device is free from problems attributable to oppositely charged toner particles despite the use of the single-component type toner and, in addition, insures attractive images.