Method for removing foreign matter from surface of glass substrate

Provided is a method suitable for the removal of dross, and in particular mold-remnant dross, present in the surface of a glass substrate manufactured using a float process. The method for removing foreign matter from the surface of a glass substrate is characterized in that: at least one metal selected from the group consisting of zinc, iron, and aluminum, and an inorganic acid aqueous solution having a pH of 3 or less and containing at least one type of ion selected from the group consisting of chlorine ions, iodine ions, bromine ions, fluorine ions and sulfuric acid ions are each supplied, so that the amount of the inorganic acid and the metal supplied per unit area is at least 1g/m2, to the glass substrate surface that makes contact with the molten metal bath when manufacturing a glass substrate using a float process; and after the surface has been etched, the etched surface is subjected to mechanical or chemical polishing so that the polishing amount is 0.1-2[mu]m.