PURPOSE: To provide a heat-resistant, multilayered printed-circuit board enhanced in adhesion and causing no haloing by formation of copper sulfide and corrosion prevention instead of blackening.

CONSTITUTION: A circuit pattern is formed on a two-sided metal-clad laminate having an epoxy-glass or polyimideglass base. The surface of the pattern, after roughened, is subjected to acid rinse and degreasing, and the laminate is immersed in a solution of a sulfur-metal salt and an alkaline substance; for example, a combination of potassium sulfide and sodium hydroxide or ammonium chloride. Inner layers are composed of copper sulfide, containing less than 10% oxygen and subjected to corrosion prevention with benzotriazole. The bonding sheets used are made of fluororesin, or semicured prepreg comprising fiberglass impregnated with resin such as epoxy or polyimide. The inner layers, bonding sheets and outer metal foil are integrally joined into a laminate, which serves as a reliable printed-circuit board.