A surface-treated steel sheet comprising: a tin-plated steel sheet obtained by tin-plating a steel sheet; a phosphate compound layer containing tin phosphate formed on the tin-plated steel sheet; and an aluminum-oxygen compound layer formed on the phosphate compound layer, a main constituent of aluminum-oxygen compound layer being an aluminum-oxygen compound, wherein, when the 3d 5/2 spectrum of tin in the aluminum-oxygen compound layer is determined using an X-ray photoelectron spectroscopy, the ratio of the integration value of the profile derived from tin oxide to the integration value of the profile derived from tin phosphate (tin oxide/tin phosphate) is 6.9 or more, characterized in that the aluminum-oxygen compound layer contains phosphate; and a ratio P/Al of the amount of phosphorus, in mol/m 2, to the amount of aluminum, in mol/m 2, in the aluminum-oxygen compound layer is 0.06 to 0.35, the amount of phosphorus and the amount of aluminum are measured using an X-ray fluorescence spectrometer, the 3d 5/2 spectrum of tin is analyzed by a waveform separation using software, a measurement apparatus for measuring the 3d 5/2 spectrum of tin is JPS-9200 manufactured by JEOL Ltd., an excited X-ray source when measuring the 3d 5/2 spectrum of tin is MgKα voltage 12 kV, current 25 mA, measurement diameter when measuring the 3d 5/2 spectrum of tin is 3 mm, a photoelectron take-off angle when measuring the 3d 5/2 spectrum of tin is 90° - equivalent to 0° with respect to the normal of the sample, an analysis software for analyzing the 3d 5/2 spectrum of tin is SpecSurf (ver. 1.7.3.9) manufactured by JEOL Ltd., and waveform separation conditions for an analysis of the 3d 5/2 spectrum of tin are binding energy of tin oxide 487.5 eV, binding energy of tin phosphate 489.1 eV, and binding energy of metal tin 485.4 eV. a tin-plated steel sheet obtained by tin-plating a steel sheet; a phosphate compound layer containing tin phosphate formed on the tin-plated steel sheet; and an aluminum-oxygen compound layer formed on the phosphate compound layer, a main constituent of aluminum-oxygen compound layer being an aluminum-oxygen compound, wherein, when the 3d 5/2 spectrum of tin in the aluminum-oxygen compound layer is determined using an X-ray photoelectron spectroscopy, the ratio of the integration value of the profile derived from tin oxide to the integration value of the profile derived from tin phosphate (tin oxide/tin phosphate) is 6.9 or more, characterized in that the aluminum-oxygen compound layer contains phosphate; and a ratio P/Al of the amount of phosphorus, in mol/m 2, to the amount of aluminum, in mol/m 2, in the aluminum-oxygen compound layer is 0.06 to 0.35, the amount of phosphorus and the amount of aluminum are measured using an X-ray fluorescence spectrometer, the 3d 5/2 spectrum of tin is analyzed by a waveform separation using software, a measurement apparatus for measuring the 3d 5/2 spectrum of tin is JPS-9200 manufactured by JEOL Ltd., an excited X-ray source when measuring the 3d 5/2 spectrum of tin is MgKα voltage 12 kV, current 25 mA, measurement diameter when measuring the 3d 5/2 spectrum of tin is 3 mm, a photoelectron take-off angle when measuring the 3d 5/2 spectrum of tin is 90° - equivalent to 0° with respect to the normal of the sample, an analysis software for analyzing the 3d 5/2 spectrum of tin is SpecSurf (ver. 1.7.3.9) manufactured by JEOL Ltd., and waveform separation conditions for an analysis of the 3d 5/2 spectrum of tin are binding energy of tin oxide 487.5 eV, binding energy of tin phosphate 489.1 eV, and binding energy of metal tin 485.4 eV.