An etchant for copper and copper alloys, includes an aqueous solution
containing: 14 to 155 g/liter of cupric ion source in terms of a
concentration of copper ions; 7 to 180 g/liter of hydrochloric acid; and
0.1 to 50 g/liter of azole, the azole including nitrogen atoms only as
heteroatoms residing in a ring. A method for producing a wiring by
etching of copper or copper alloys, includes the step of: etching a
portion of a copper layer on an electrical insulative member that is not
covered with an etching resist using the above-described etchant so as to
form the wiring. Thereby, a fine and dense wiring pattern with reduced
undercut can be formed.