This paper deals with the preservation of Onoda Bottle Kiln which was built in Taiheiyo Cement Factory in Onoda City. Cementitious rendering which had been spread partly on the furnace of the kiln until January 1999, were removed for repairing deteriorations. As a result, the old brick walls were found under the cementitious rendering. It was different from the other parts in bonding pattern. October 2000, the excavation started around the kiln so that three clay brick masonry foundations connected with the existing kiln and two small foundations in the east and one foundation in the west were found. From these investigation results and textual material, the existing kiln was clarified to have been built in 1883 (Meiji 16).