Abstract: In a dry etching system, a method of cleaning an etching chamber allows a series of steps of introducing a wafer, selectively dry-etching an aluminum film provided on the wafer, cleaning the etching chamber by etching gas containing oxygen gas and capable of removing remaining chlorine, and ashing resist to be executed continuously with each of consecutive wafers without exposing them to the atmosphere. The etching and cleaning steps are completed within a period of time necessary for the ashing step. This not only protects the resulting aluminum wirings on the wafers from corrosion but also saves time otherwise consumed by the cleaning step, thereby increasing the throughput of the system.