In this paper, we propose a wafer position error recognition system using computer vision technology and radial shape board. Wafer is one of the material when create the semiconductor. Wafer must be cleaned by the chemical during creating the semiconductor process .In this step, the robot moves wafer into the cleaning system. But sometime, the robot puts the wafer into an incorrect location. In this case, the trouble of cleaning system may be caused by the incorrect position, even the wafer can be broken. To prevent this case, we are going to find the wafer position in cleaning system using the computer vision technology. We perform the calibration and image processing for knowing the correct position of wafer. In calibration process, we are going to use the radial shape board.