A method of manufacturing a semiconductor integrated circuit device wherein a conductor film is formed on a front surface of a substrate by a lift-off technique; comprising forming a first resist film on that area of the substrate surface on which the conductor film is not formed, forming a second resist film on the whole substrate surface including the first resist film and a conductor film forming area of the substrate surface, providing a first opening for forming the conductor film in a conductor film forming area of the second resist film and also providing a second opening for forming a dummy conductor film in that area of the second resist film in which the conductor film is not formed, depositing the conductor film on the whole substrate surface including the substrate surface inside the first opening, the first resist film inside the second opening and the second resist film, and removing the second resist film and the first resist film respectively, so as to leave the conductor film inside the first opening and to remove the conductor film on the second resist film and the dummy conductor film on the first resist film.