Grinding machine for processing workpieces which are preferably in at least one section made of wood, wood composite materials, plastics, metals and the like materials, having: - at least one grinding unit with a preferably vertically adjustable grinding device, for grinding a workpiece; - a conveying device for conveying the workpiece in a direction of throughput through the at least one grinding unit; - a control device which is suitable for matching the operation of the at least one grinding unit to a nominal finished thickness of the workpiece; - a second thickness determining device which is arranged in front of the at least one grinding unit in the direction of throughput, wherein with the second thickness determining device an actual base thickness of the unprocessed workpiece can be determined; characterised in that: - the grinding machine further has a thickness determining device which is arranged after the at least one grinding unit in the direction of throughput, and with which an actual finished thickness of the workpiece processed by the at least one grinding unit can be determined; - the control device is further suitable for comparing the actual finished thickness of the workpiece with the nominal finished thickness and controlling the operation of the at least one grinding unit in such a way that the actual finished thickness is adapted to the nominal finished thickness; and - the control device is further suitable for comparing the actual base thickness of the workpiece with a nominal base thickness, and on this basis controlling the operation of the at least one grinding unit in such a way that a thickness of the processed workpiece is in general adapted as far as possible to the nominal finished thickness, and performing adaptation of the actual finished thickness of the workpiece to the nominal finished thickness and adaptation on the basis of the comparison of the actual base thickness with the nominal base thickness by output of a total grinding depth to the at least one grinding unit. - at least one grinding unit with a preferably vertically adjustable grinding device, for grinding a workpiece; - a conveying device for conveying the workpiece in a direction of throughput through the at least one grinding unit; - a control device which is suitable for matching the operation of the at least one grinding unit to a nominal finished thickness of the workpiece; - a second thickness determining device which is arranged in front of the at least one grinding unit in the direction of throughput, wherein with the second thickness determining device an actual base thickness of the unprocessed workpiece can be determined; characterised in that: - the grinding machine further has a thickness determining device which is arranged after the at least one grinding unit in the direction of throughput, and with which an actual finished thickness of the workpiece processed by the at least one grinding unit can be determined; - the control device is further suitable for comparing the actual finished thickness of the workpiece with the nominal finished thickness and controlling the operation of the at least one grinding unit in such a way that the actual finished thickness is adapted to the nominal finished thickness; and - the control device is further suitable for comparing the actual base thickness of the workpiece with a nominal base thickness, and on this basis controlling the operation of the at least one grinding unit in such a way that a thickness of the processed workpiece is in general adapted as far as possible to the nominal finished thickness, and performing adaptation of the actual finished thickness of the workpiece to the nominal finished thickness and adaptation on the basis of the comparison of the actual base thickness with the nominal base thickness by output of a total grinding depth to the at least one grinding unit.