drum 5a the above mentioned image forming process is repeated with respect to magenta toner cyan toner yellow toner and black toner respectively so that the four different color toner images are successively transferred onto the recording sheet p in a superimposed fashion thereafter the recording sheet p is separated from the transfer drum 5a and the separated recording sheet is sent to a fixing device where the four different color toner images are fused and mixed to obtain a full color image next a transfer device having the transfer drum will be fully explained in fig1 a transfer sheet recording sheet bearing member 5f for electrostatically absorbing the recording sheet and for conveying the recording sheet in a direction shown by the arrow c is wound around a peripheral surface of the transfer drum 5a in such a manner that tip and rear ends of the transfer sheet 5f are adhered to a connecting member 5j of the transfer drum 5a in the illustrated embodiment the transfer sheet 5f is formed from a flexible pc polycarbonate film having a thickness of 150 u03bcm and a volume resistance of 10 15 u03c9cm or more because an absorbing force for absorbing the recording sheet to the transfer sheet 5f is improved by using the dielectric film having high volume resistance as the transfer sheet accordingly it is possible to use a thick sheet as the recording sheet and to increase a process speed.