The invention is directed to a dry-etching apparatus used for etching an aluminum wiring film formed on a wafer, and more particularly to a dry-etching apparatus which can remove chlorides deposited on the surface of the wafer during the dry etching thereof, as well as an etching resist film, without having to take the wafer out. This dry-etching apparatus is provided with an etching chamber, a vacuum antechamber attached to the etching chamber by a gate valve, and a post-treatment chamber attached to the vacuum antechamber. The apparatus is so formed that etched wafers removed to the vacuum antechamber can be sent therefrom to the post-treatment chamber, and then the post-treated wafers can be removed to the vacuum antechamber again, and then removed therefrom to the atmosphere.