Surface-treated steel sheet

A surface-treated steel sheet comprising:

• a plating layer located on at least one surface of a steel sheet and containing zinc and nickel;
• a first composite layer located between the steel sheet and the plating layer and containing Fe, Zn, and Ni;
• a chromium-containing composite layer located on the plating layer and containing at least Cr;
• and
• a paint film located on the chromium-containing composite layer and containing an epoxy resin, an isocyanate resin, and a silica particle, wherein:
• an amount of the plating layer is 2 to 50 g/m2 per single side;
• the chromium-containing composite layer includes
• a second composite layer located on the plating layer side and containing Cr, Zn, and Ni, and
• a third composite layer located on the paint film side and containing Si, N, and Cr;
• an amount of the chromium-containing composite layer is 10 to 200 mg/m2 in terms of metal Cr;
• and
• a thickness of the paint film is 0.5 to 2.0 μm.