It is to provide a method for removing a tin defect present on the surface of a glass substrate produced by a float process in a short time without the glass substrate surface being damaged regardless of the glass temperature.A method for removing a tin-containing foreign matter from the surface of glass, which comprises applying to the surface of a glass substrate produced by a float process a pulse laser beam having a transmittance of at least 70% through the glass substrate and having a pulse width, a wavelength and an energy density per unit area on the glass substrate surface which satisfy specific relations, to remove a tin-containing foreign matter present on the rear face opposite to the face irradiated with the pulse laser beam.