This invention relates to an etching solution including hydrogen peroxide, sulfuric acid, chlorine ions, benzotriazole and pyrazole, and to a method of manufacturing a printed wiring substrate wherein the surface of the metal wiring of the printed wiring substrate is treated with an alkali solution, roughened using the etching solution and then subjected to anti-rust treatment, thus forming porous surface irregularities and micro anchors even with a small etching amount of the metal (Cu) to thereby obtain a high force of adhesion between the metal and an insulating material.