Producing a circuit board, by laminating, on a substrate, an
adhesive film with a
metal film, which comprises a water-
soluble polymer release layer, a
metal film layer and a curable resin composition layer, which are formed in this order on a support layer, and has a release property enabling detachment of said water-
soluble polymer release layer from the support layer after curing of the curable resin composition layer, such that the curable resin composition layer contacts the substrate; curing the curable resin composition layer; detaching the support layer, and removing the water-
soluble polymer release layer present on the
metal film layer by dissolving the release layer in an
aqueous solution, efficiently forms an insulating layer and a metal film layer superior in adhesiveness to the insulating layer and in uniformity. By this method, a metal film layer having high adhesiveness and high property uniformity can be formed on the surface without the need for roughening the surface of an insulating layer with an oxidant such as alkaline
potassium permanganate solution and the like. Thus,
etching for circuit formation can be performed under milder conditions, which in turn provides a superior effect on micro wiring on circuit boards such as multi-layer printed wiring boards, flexible printed wiring boards, and the like.