PURPOSE: To accurately align wafers upward while the orientation flat (OF) of the wafer remains inserted into a cassette by rotating a rotational shaft raised to the first position, directing the OF of the wafer in the cassette downward, then raising the shaft to the second position, and rotating to direct the OF upward.

CONSTITUTION: A cassette 6 which contains a wafer 1 is set on a cassette washer 11. At this time an OF 2 is disposed at random, and not constant. The first air cylinder is operated to raise elevation plates 25, 31, a sleeve 36 coated on a main shaft is raised from a reference position, and the outer surface is contacted with the lower end of the outer periphery of the wafer 1 in the cassette 6. When the sleeve 36 is rotated together with the main shaft, the OF 6 of the wafer 1 is directed downward. Then, the second air cylinder 32 is operated to raise the plate 31, the sleeve 36 is contacted with the OF 2 to rotate the wafer 1, and the OF 2 is directed upward.