In order to provide an anticorrosive technique for metal wirings formed by a chemical mechanical polishing (CMP) method, a process for manufacturing a semiconductor integrated circuit device according to the invention comprises the steps of: forming a metal layer of Cu (or a Cu alloy containing Cu as a main component) over the major face of a wafer and then planarizing the metal layer by a chemical mechanical polishing (CMP) method to form metal wirings; anticorroding the planarized major face of the wafer to form a hydrophobic protective film over the surfaces of the metal wirings; immersing the anticorroded major face of the wafer or keeping the same in a wet state so that it may not become dry; and post-cleaning the major face, kept in the wet state, of the wafer.