The invention provides a method for chemical conversion treatment by which a chemical conversion layer attaining satisfactory substrate-covering properties, adhesion to coating and corrosion resistance can be formed on any metal structure surface. A method for chemical conversion treatment by treating a metal structure with an agent for chemical conversion treatment, wherein the agent contains zirconium, fluorine, an amino -containing alkoxysilane, and a hydroxyl-containing alkoxysilane with the contents of zirconium and the amino-containing alkoxysilane being 100 to 700 ppm in terms of metal and 50 to 500 ppm in terms of solid matter respectively at a fluorine/zirconium molar ratio of 3.5 to 7.0 and has a pH of 2.8 to 4.5.