PURPOSE: To stably form metal wirings having a desired width and a taper on the edge of its upper face by forming a photoresist to become a mask in a 2-layer structure employing its upper layer having higher resist sensitivity, forming the lower layer in a predetermined wiring width and the upper layer in finer width than a predetermined wiring width, and conducting its anisotropic dry etching.

CONSTITUTION: After a substrate 1 is covered as a wiring metal film 2 with Al-Cu or Al-Si-Cu, a first photoresist film 3 and a second photoresist film 3' having a sensitivity higher than that of the first film are sequentially laminat ed thereon, and formed. Then, when it is anisotropic dry etched with mixture gas of BCl3, Cl2, etc., from above the resist mask and it is continuously etched under the same condition or the condition of slightly lower selection ratio than that of the resist, the extended part of the resist lower layer film from the upper layer film is eliminated. When the edge of the wiring pattern of the film 2 is further etched and the resist film is removed, a metal wiring having a tapered shape is obtained at the edge of the upper face thereof.