An object is to provide a method for teaching the position of a semiconductor wafer automatically and accurately without relying on the sight of an operator as well as a teaching jig that is used for the above method.To this end, in the invention, a teaching jig 11 is detected by a first transmission-type sensor 6 that is provided at the tips of a wafer gripping portion 5 of a robot. The teaching jig 11 is composed of a large disc portion 12 that is the same in outer diameter as a semiconductor wafer and a small disc portion 13 that is concentric with the large disc portion 12. The teaching jig 21 is detected by a second transmission-type sensor 18 that is provided on the wafer gripping portion 5. The second transmission-type sensor 18 is mounted on a sensor jig 15 so as to be detachable form the wafer gripping portion 5.