An image forming apparatus has a charging device for charging a photosensitive member containing an organic photoconducter, an exposure device, a developing device including a developer, a transfer device and a cleaning device. The photosensitive member employs an organic photoconductor and a polycarbonate resin layer which forms the surface of the photosensitive member. The developer device has a sleeve with a thin layer of an electrical coating material containing dispersed carbon particles. The developer contains insulating magnetic toner particles of relatively small particle size formed from a styrene-acrylic type copolymer or a polyester resin and a magnetic powder.