To provide a method for efficiently and economically performing polishing work for removing defects such as orange peel, flaws and the like for smoothing and making glossy the surface of a skin sheet of an aircraft.

This method includes the step of performing sand paper polishing the outer surface of an aircraft part by a mechanical sand paper polishing machine to remove most of defects, the step of removing the defects not removed in the sand paper polishing step or the other defects, which is an intermediate finishing step for one or plural times, and a step of polishing and finishing the surface which has been sand paper polished plural times by a finishing polisher.