Airplane reservoirs made of Al7075 are coated with an anodizing layer to maintain precision for air tightness and for corrosion resistance. It is commonly required that the inner surface roughness of the reservoir be less than an average of 0.2㎛ to maintain stable oil pressure. This requires precision polishing, but achieving this quality is not easy. Because most of the polishing work is done by hand, the inner surface roughness is not uniform and the quality of the product is irregular. In addition, the entire manufacturing process is inefficient because the polishing processes must be repeated. In this study we experimentally investigated methods to eliminate redundancies in the polishing process. We found that the most effective way to achieve less than Ra0.2㎛ roughness was in the turning process, before the first polishing process. We also designed an exclusive automated-polishing machine to perform a second polishing process, using the CATIA program. Using the polishing machine we experimentally determined the optimum polishing film process for anodized Al7075 and achieved better results than those obtained by the repeated hand polishing process.