PROBLEM TO BE SOLVED: To provide a method for manufacturing a surface-treated steel sheet yielding, by inhibiting the depletion of the organic polymer concentration within a surface treatment bath, an excellent adhesiveness of a surface treatment film and an organic resin coating layer coated atop the former.SOLUTION: In a method for manufacturing a surface-treated steel sheet where a film including an oxygen compound of zirconium and a polycarboxylic acid or polycarboxylate is formed, by performing an electrolytic treatment, atop an iron-bared steel belt by using a surface treatment bath including zirconium ions and a polycarboxylic acid or polycarboxylate but including no chromium, an iron precipitant is included within the surface treatment bath so as to inhibit/control the depletion of the concentration of the polycarboxylic acid or polycarboxylate within the surface treatment bath and to abate the concentration of iron ions eluted into the surface treatment bath from the steel belt.