A device for developing an electrostatic latent image recorded on a photoconductive layer. The developing device comprises a doner roll for supporting a uniform layer of single-component developing material adjacent to the photoconductive layer. The doner roll is disposed as to create a space gap between the photoconductive layer and the doner roll. The doner roll is made of semiconductive material having a specific resistance ranging from 106 to 1012 OMEGA cm. An electrical bias potential is applied across the gap, thereby establishing a field for transferring the developing material from the doner roll to the photoconductive layer.
