Patent ID: 8545158

Claim:
A loading unit for housing a substrate holder for holding plurality of substrates and a cap for supporting the substrate holder, and vertically moving the substrate holder and the cap into and out of a cylindrical processing container having a bottom opening to be closed by the cap, said loading unit comprising: a lifting elevator mechanism configured to hold and vertically move the substrate holder and the cap; and a pressing mechanism, having a piezoelectric actuator, configured to upwardly press against the cap lying at the bottom opening of the processing container, wherein the pressing mechanism is arranged independently from the lifting elevator mechanism and assists the lilting elevator mechanism in upwardly moving the substrate holder and the cap, wherein the pressing mechanism includes a fixed arm portion, and a slide plate provided in the fixed arm portion and configured to be horizontally movable below the cap positioned at the opening, and wherein the piezoelectric actuator is provided on the slide plate and is capable of pressing against the cap.