A chemical mechanical polishing stopper film comprising at least one organic polymer, said film having a dielectric constant of 4 or lower, and a chemical mechanical polishing method. The chemical mechanical polishing method comprises forming a chemical mechanical polishing stopper film comprising at least one organic polymer on an insulating film so that the stopper film is interposed between the insulating film and a metal film to be removed by chemical mechanical polishing, and then removing the metal film with a chemical mechanical polishing slurry.