Abstract: On the surface of a semiconductor wafer there is formed a binary-coded pattern which has high and low reflection portions and which contains an item of wafer processing information. A scanning device is provided to scan such patterns on individual wafers in order to obtain items of scanned information. Further a control device is provided to store the items of wafer processing information. Upon receipt of an item of scanning information, the control device produces a control signal which corresponds to the item of scanning information. The control signal is supplied to one of wafer processors, which effects on the semiconductor wafer the process necessary to manufacture a semiconductor device.