PURPOSE: To prevent contamination and to prevent damage of a wafer, by using a wafer mouting stage for taking the wafer out of a wafer carrier for conveyance and for accommodating the wafer after treatment.

CONSTITUTION: A wafer mounting stage 11 has a diameter, which is smaller than a wafer 100 by several mm and also smaller than an interval between the side walls of a wafer carrier 104. The wafer mounting stage is mounted on a belt 103. When the rotating direction of the wafer mounting stage 11 is reversed, the wafer can be freely returned to the wafer carrier. When wax is applied on the upper surface of the wafer during the rotation of the wafer, the outer edge of the wafer is held with pawls, and the wafer is put on the wafer mounting stage 11. Even if the wax is attached to the outer edge of the wafer, the wafer mounting stage is not contaminated.