An image forming apparatus capable of preventing a sheet from falling during jam handling without adding a special mechanism. The apparatus has an openable door forming a guide wall of a first path in a closed state. A first pair of rollers are disposed on the first path for nipping and conveying a sheet in a door closed state, and separated from each other when the door is opened. A second path is connected to the first path, for conveying downstream a sheet from the first path. A second pair of rollers disposed on the second path can keep nipping a sheet even when the door is opened. If a jam occurs, a sheet remaining in the first path is conveyed into the second path using the first roller pair, and is nipped by the second roller pair.