A polishing method comprises supplying a polishing liquid to an upper portion of a film to be polished to carry out first polishing, the film being provided on a layer having a groove with a predetermined pattern so as to be filled therewith, after the first polishing, polishing the film to carry out clean polishing while supplying one of distilled water and a cleaning liquid thereto, and after the clean polishing, polishing a residual portion of the film remaining outside of the groove by supplying a polishing liquid to carry out second polishing.