time since the occurrence of an operational error the residual toner particles on the peripheral surface of the photosensitive drum 1 are no longer holding electrical charge and therefore it is impossible to remove the residual toner particles from the peripheral surface of the photosensitive drum 1 by electrostatically transferring them onto the transfer sheet surface through a transfer process thus in the case of the present invention once a substantial length of time elapses after the occurrence of an error the residual toner particles on the peripheral surface of the photosensitive drum 1 are removed based on the following principle with the condition that a user removes the transfer medium which has been jammed in the apparatus main assembly after the removal of the jammed transfer medium by a user the residual toner particles on the peripheral surface of the photosensitive drum 1 are frictionally charged between the photosensitive drum 1 and the transfer roller 4 the residual toner particles are recharged by driving the photosensitive drum 1 charge roller 2 and development roller 3 transfer roller 4 and the like at the same time voltage of negative polarity that is the same polarity as the polarity to which the residual toner particles are charged is applied to the transfer roller 4 since the potential of.