In order to develop a corrosion-free halogen gas delivery system for use in semiconductor manufacturing, Cr2O3 passivation of ferritic and austenitic stainless steels has been investigated. It has been shown that a Cr2O3 layer can be formed on an electropolished (EP) surface of ferritic 26Cr-1Mo stainless steel by oxidation above 600 degrees C, but excellent corrosion resistance performance to Cl-2 gas can be obtained only by oxidation above 700 degrees C. On the other hand, on the EP surface of austenitic SUS 316L, a corrosion-resistant Cr2O3 layer is not formed by oxidation even up to 800 degrees C.