PROBLEM TO BE SOLVED: To provide a method for forming a polymer compound layer and a pattern of a thin gold plating layer which has no defect on a desired portion of a stainless substrate.SOLUTION: The forming method includes: a first plating step of pretreating a stainless substrate 1, and subsequently forming a first gold plating layer 11 on a whole surface or the desired portion by using a hydrochloric acid plating solution; a polymer compound layer forming step of providing a polymer compound layer 15 by melting and crimping a polymer compound on the desired portion of the first gold plating layer; a second plating step of forming a second gold plating layer 12 into a desired pattern by mask plating on the first gold plating layer of a region in which the polymer compound layer does not exist; and subsequently, peeling step of peeling and removing the second gold plating layer and the first gold plating layer of the region in which the polymer compound layer does not exist by using an alkali-based peeling
