The glass sheet production method of the present invention includes the steps of: (I) bringing a mixed gas into contact with at least one surface of a sheet-shaped glass material so as to change a surface morphology of the glass material to an extent that light scattering properties of the glass material are changed, the mixed gas containing a fluorine element (F)-containing acid A and a chlorine element (Cl)-containing acid B and having a molar ratio of water to the acid A (molar concentration of water / molar concentration of acid A ) of less than 5, the glass material containing at least sodium as a component and having a temperature in a range from a glass transition temperature to a temperature 300°C higher than the glass transition temperature; and (II) cooling the sheet-shaped glass material obtained in the step (I) so as to obtain a glass sheet.