PURPOSE: To prevent the generation of a polymer residue, by leaving an interlayer insulation film between an aluminium wiring and the bottom part of a through hole through an anisotropic dry etching, and by removing a resist film through a reactive ion etching wherein a gas containing oxygen as its main component is used.

CONSTITUTION: When a through hole 8 is formed by an anisotropic dry etching, a part of an interlayer insulation film 1 is so left between a first aluminium wiring 2 and the bottom part of the through hole 8 that the first aluminium wiring 2 is not exposed to the outside. Thereby, the generation of a polymer residue is prevented. Also, by a reactive ion etching through a gas containing oxygen as its main component, a resist film 3 is removed. Thereby, by virtue of a taper formed in the opening part of the through hole 8, a second aluminium wiring 10 is formed with a good coverage. Therefore, the manufacturing processes of a semiconductor are simplified.