PURPOSE: To produce the surface-treated steel plate excellent in corrosion resistance, weldability and coating adhesion (printability) at a low cost by a coating method without using any electrolysis.

CONSTITUTION: This surface-treated steel plate is provided with a coating film which is formed on the surface of an untreated steel plate by a coating method and consists essentially of trivalent chromium oxide and has a 0.1 to 1μm thickness. The coating film also contains oxide of at least one metal (Me) selected from among alkaline earth metals and aluminum in an amount to provide a Me/Cr metallic element molar ratio of 0.1 to 1.5 and if necessary, further contains SiO2 in an amount to provide a Si/Cr metallic element molar ratio of ≤1.0. This coating film is formed on the untreated steel plate by applying and baking a liquid coating material contg. a hexavalent chromium compound, a reducing agent and an Me source and further if necessary, SiO2.