PURPOSE: To provide the transfer device of an image forming machine provided with a driving mechanism automatically correcting the moving speed of a transfer belt to be the circumferential speed of an image carrier even when speed difference occurs between the circumferential speed of the image carrier and the moving speed of the transfer belt.

CONSTITUTION: The transfer device 6 of the image forming machine is provided with a driving roller 63 coupled to be conducted to a driving device, a driven roller 64 disposed by leaving a gap between the rollers 63 and 64, the transfer belt 68 spread between the rollers 63 and 64 and disposed to be faced to the image carrier 3 and a toner cleaning means 80 cleaning the surface of the belt 68. Besides, it is provided with a torque limiter disposed between the rotary shaft of the roller 63 and the driving device 30. The limit torque of the torque limiter is set to be smaller than driving force between the carrier 3 and the belt 68 and larger than resistance by the cleaning means 80 acting on the belt 68.