The method of fabrication of a liquid crystal display device includes the steps of: forming a metal thin film on a glass substrate; forming a resist pattern on the metal thin film by photolithography; and wet-etching the metal thin film with an etchant formed of a mixture including phosphoric acid, nitric acid in a range between 7 mol % and 12 mol % inclusive, and at least one of ammonium fluoride and hydrogen fluoride in a trace amount of about 0.01 to 0.1 mol %.