Provided is a plated steel sheet combining yield point ratio, strength (tensile strength), elongation, hole expansion and CTS. Also provided is a method for producing same. The thin steel sheet has a specific component composition, and a metal microstructure which, by volume percentage, contains 70-90% ferrite, 5-20% martensite, no more than 5% residual austenite, no more than 10% bainite, and no more than 5% pearlite, with the average crystal grain size of the ferrite not exceeding 20 µm, the average crystal grain size of the martensite not exceeding 5 µm, the average crystal grain size of the residual austenite not exceeding 5 µm, and the average crystal grain size of the bainite not exceeding 7 µm. The tensile strength of the thin steel sheet is at least 590 MPa.