Dry air is jetted from jet holes of a guide plate toward a conveyor belt to levitate a photosensitive sheet and to press it against the conveyor belt. The photosensitive sheet is supported and carried by the conveyor belt. The dry air dries the photosensitive sheet. A projection amount h of a guide roller projecting from the guide plate is defined so as to satisfy an expression of h.gtoreq.H.times.(W-P)/W. H is a gap between the guide plate and the conveyor belt. P is a length from a center line of the carried photosensitive sheet to an outer edge of the guide roller. W is a length from the center line to a lateral end of the photosensitive sheet. Even if a curl occurs on the photosensitive sheet, an edge thereof is prevented from contacting with the guide plate.