An image forming apparatus that facilitates user's determination of necessity of setting an inspection resuming page and is improved in jam processing efficiency. A sheet having an image formed thereon by an image forming unit is conveyed along a sheet conveying path. A sheet inspection device inspects the image on a sheet being conveyed through sheet conveying path. When a jam occurs in the conveying path, image formation by the image forming unit is interrupted. When jammed sheets are removed, formation of images including those formed on the jammed sheets is resumed. When a leading one of the jammed sheets is on a downstream side of the sheet inspection device, the image formation is resumed from an image formed on the leading jammed sheet, based on a user instruction.