The invention provides a dry etching method for performing a wiring process on a semiconductor substrate using a plasma etching apparatus, wherein the wiring process is performed without causing disconnection or deflection of the wiring. The invention provides a dry etching method for performing a wiring process on a semiconductor substrate using a plasma etching apparatus, wherein during a step for etching a material 12 to be etched using a mask pattern composed of a photoresist 15 and inorganic films 14 and 13 made of SiN, SiON, SiO and the like formed on the material 12 to be etched, a mixed gas formed of a halogen-based gas such as chlorine-containing gas or bromine-containing gas and at least one fluorine-containing gas selected from a group of fluorine-containing gases composed of CF4, CHF3, SF6 and NF3 is used to reduce the mask pattern and the processing dimension of the material to be etched substantially equally during processing of the material 12 to be etched.