An etchant of the present invention includes an aqueous solution containing hydrochloric acid, nitric acid, and a cupric ion source. An etching method of the present invention includes bringing the etchant into contact with at least one metal selected from nickel, chromium, nickel-chromium alloys, and palladium. Another etching method of the present invention includes bringing a first etchant that includes an aqueous solution containing at least the following components A to C (A. hydrochloric acid; B. at least one compound selected from the following (a) to (c): (a) compounds with 7 or less carbon atoms, containing a sulfur atom(s) and at least one group selected from an amino group, an imino group, a carboxyl group, a carbonyl group, and a hydroxyl group; (b) thiazole; and (c) thiazole compounds; and C. a surfactant) into contact with a surface of the metal, and then bringing a second solution that includes an aqueous solution containing hydrochloric acid, nitric acid, and a cupric ion source into contact with the surface of the metal. According to the etchant and the etching methods of the present invention, it is possible to etch at least one metal selected from nickel, chromium, nickel-chromium alloys, and palladium quickly and suppress excessive dissolution of copper.