An image forming apparatus includes an image former forming a toner image on a long sheet; a main conveyance path conveying the long sheet to the image former; and a double-side conveyance path which branches off from a first side, in the main conveyance path, downstream of the image former in a conveyance direction of the long sheet, and which conveys the long sheet to a second side upstream of the image former by reversing the conveyance direction at a point of switching back to invert the long sheet. The double-side conveyance path includes, in a downstream side in the conveyance direction before the switching back, a merging pathway connected to the second side upstream of the image former in the main conveyance path, and a first introducer introducing into the merging pathway a head of the long sheet in the conveyance direction before the switching back.