Abstract: The invention provides a method of forming an electrode or wiring which prevents reattachment of an etching residue in following processes by removing the etching residue at a bevel portion of a semiconductor wafer. An insulation film is formed so as to cover a front surface and a back surface of a semiconductor wafer, and then a conductive film is formed on a whole surface of the insulation film. Next, a photoresist layer is selectively formed on the conductive film by an exposure and development process. The conductive film is then selectively removed by an isotropic etching with using this photoresist layer as a mask, thereby forming an electrode or wiring of a semiconductor device. Since the electrode or the wiring of the semiconductor device is formed by isotropically etching the conductive film, a hangnail-like etching residue causing dust does not occur at the bevel portion of the wafer even though the conductive film remains on the back side of the semiconductor wafer.