The calibrating and sanding machine is used in the processing of the wooden piece in order to calibrate and/or sand the latter with the result of making it smooth and ready for a possible finish. The calibration phase allows to reduce the thickness of the panel by removing a layer and making it perfectly straight; sanding instead makes the surface completely smooth. Both phases are carried out by passing the piece underneath abrasive belts which are more or less hard depending on how much material is to be removed and the type of wood to be worked.