PURPOSE: To obtain high image quality free from a missing of an image and irregularities in the image and also to improve a paper carrying performance by setting the outer surface resistance which comes in surface-contact with a transfer material larger than the inside surface resistance.

CONSTITUTION: The transfer belt 1 is laid between a driving roller 2 and a driven roller 3, and the belt is electrostatically charged by applying a system for directly impressing a voltage by a bias roller 8, etc. And a series of operations is performed by the transfer belt that the paper 5 carried by a resist roller 4 is received, and then, the paper is pressed against a photoreceptor drum 6 so that a toner image may be transferred, thereafter, the transferred paper 5 is delivered to a fixing device 7 constituted of a fixing roller 7a and a pressure roller 7b. Then, the outer surface resistance which comes in surface- contact with the paper 5 of the transfer belt 1 is set larger than the inside surface resistance. For example, when the inside surface resistance is 105 to 1010Ω and also the surface resistance on a coat side is 108 to 1012Ω the image is kept in a good state, and also, the carrying performance for the paper 5 is improved.