A method for manufacturing a printed circuit board enables a metal residue between wirings to be removed inexpensively without side etching of a copper layer while having sufficient insulation reliability for micro wiring working. The method includes forming a base metal layer directly at least on one face of an insulator film without an adhesive, and a copper coat layer formed on the base metal layer to form adhesiveless copper clad laminates, then forming a pattern on the adhesiveless copper clad laminates by an etching method. The etching method includes a process of etching treatment for the adhesiveless copper clad laminates with an iron (III) chloride solution or a copper (II) chloride solution containing hydrochloric acid and then, a process of treatment with an acid oxidant containing potassium permanganate.