a single - station thermoforming apparatus is provided with at least an oven including a heating panel , formed by two panel portions which can be driven on a plane parallel to the laying plane of a plastics material sheet to be thermoformed and which can be mutually coupled at a common coupling line , thereby providing an even distribution of heat through the overall surface of the plastics material sheet being processed , and preventing any thermal differentials among different regions of the material sheet being processed .