An image forming apparatus that includes an image reading part to read an image of an original, an image recording part to record the image read by the image reading part on a sheet, a sheet discharge part to discharge the sheet recorded by the image recording part from front to rear of a main body of the image forming apparatus, a sheet stack part to stack the sheet discharged by the sheet discharge part between the image reading part and the image recording part, first and second supporters provided outside the sheet stack part along a discharge direction of the sheet to form a space between the sheet stack part and the image reading part, and a lock mechanism to lock the image reading part. The image reading part slides relative to the first and second supporters in the discharge direction.