An image forming machine having a reversing transport path in which a transport direction of a sheet introduced from an image forming transport path is reversed, a returning path in which the sheet reversely transported from the reversing transport path is returned below the image forming transport path with the directions of the face and back of the sheet being unchanged, and an inverting transport path in which the sheet from the returning path is turned upside down and readmitted into an upstream portion of the image forming transport path. A finisher including a sheet receiving stand placed below the returning path is provided, and at least one send-in unit for selectively sending in different length sheets onto the sheet receiving stand is disposed in the returning path.