A bandpass filter receives a tracking error signal. The variants have altered physicochemical properties. The apparatus also includes mounting holes in the top face for fastening engagement to the cutting machine, at least one inlet passage for connection to at least one fluid delivery nozzle, and a plurality of outlet flow passages. By doing this, frictional force of the conveyor belt with the sheets of paper P on the rear end side is made smaller, and frictional force with the sheets of paper P on the front end side is made larger, and the ejectability of sheets from the processing tray after ending of the post process is improved.