Abstract: The invention relates to a measuring device, which allows the thickness of an elongated, panel-type workpiece, lying on a reference plane and traveling along the reference plane, to be continuously recorded. The measuring device is provided with a guide shoe, which is bath-shaped and open at the top and is pivotally mounted in a machine frame on parallelogram-shaped steering elements. A measuring roller, which projects slightly out of a cavity in a base section that runs parallel to the reference plane, is located inside the guide shoe. The measuring roller is supported in the interior of the guide shoe by rollers on both sides of the recess. The measuring roller is in contact with the reference plane and after a deflection of the guide shoe, comes into contact with the measuring surface of the workpiece, a measured value that represents the thickness being derived from the deflection.