PROBLEM TO BE SOLVED: To obtain a surface-treated galvanized steel plate that achieves both corrosion resistance and discoloration resistance by using a thin surface treatment film containing no chromium compound.SOLUTION: An oxide layer having an oxide film thickness of 15-50 nm in terms of a silicon oxide film is formed on the surface layer of a galvanized layer of a galvanized steel plate. The galvanized steel plate has a surface treatment film that is formed by applying a surface treatment solution to the surface of the galvanized steel plate followed by drying. The surface treatment solution contains a silane compound (A) that is obtained from a silane coupling agent (a1) having a glycidyl group, tetraalkoxysilane (a2), and phosphonic acid (a3) and has a hydrolyzable group, a zirconium carbonate compound (B), a vanadic acid compound (C), and water at a specific ratio.SELECTED DRAWING: None
