An image forming apparatus includes an image transfer device (7) for transfering a toner image at an image transfer position on an image supporting member (P), a movable carrier (6a) for carrying the image supporting member (P) on a first side thereof and for conveying the image supporting member (P) to the image transfer position in order to perform the image transfert, an adsorption device for causing the image supporting member (P) to be electrostatically adsorbed or adhered onto the carrier device (6a). The adsorption device is provided at an upstream side of the image transfer position in the direction of move­ment of the carrier (6a). The adsorption device comprises a corona charger (19) provided at a second side of the carrier (6a) op­posite to the first side. A contact member (23) for contacting the second side of the carrier (6a) is provided adjacent to the corona charger (19); this member corrects distorsion of the movable carrier (6a).