In some preferred embodiments of the present invention, a method of performing calibration of an optical axis of a sensor installed on a hand of an arm of a robot by obtaining misalignment of the optical axis of the sensor relative to the hand or by obtaining misalignment of the hand relative to the arm is provided. A method of performing calibration by detecting a teaching tool 11 disposed at a semiconductor wafer placing position of a storage container or a carrying device by a sensor 6 installed on a hand 5 of a robot 1 to teach the position of the semiconductor wafer to the robot 1 includes a step of placing the teaching tool 11 at specified position with the robot 1, a step of predicting the position of the teaching tool 11 detecting the teaching tool 11 with the sensor 6, and a step of obtaining a difference between the position of the teaching tool 11 and the predicted value.