The present disclosure relates to a chemically treated zinc-based plated steel sheet that is superior in weather resistance, water resistance, blackening resistance and film adhesion. A chemical conversion film having a thickness 0.5-10 μm is formed by coating and drying a chemical treatment solution on a surface of an aluminum-containing zinc-based alloy plated steel sheet. The chemical treatment solution contains a fluororesin containing 0.05-5% by weight of a hydrophilic functional group selected from the group consisting of a carboxyl group and a sulfonic acid group and 7-20% by weight of a fluorine atom, the fluororesin in which a number-average molecular weight is 1,000-2,000,000, and an oxoate, a fluoride, a hydroxide, an organic salt, a carbonate or a peroxygenated salt of a group 4A metal.