“Tatara” was a Japanese traditional process to produce solid steel, so called “Kera” and/or iron pig, so called “Zuku”, from iron sand and charcoal using box type furnace with blowing cold air. Characteristics of Tatara steelmaking process are low-temperature reaction and short reduction time. Therefore, Tatara furnace is suitable to teaching material of metal smelting. In order to operate safely and get iron securely, outer wall of the Tatara furnace doubled and we used iron sand with a very small particle size. We operated the improved Tatara furnace and get spherical solid steels showing metallic luster. Carbon concentration in the steel was analyzed by infrared absorption method during oxidation to be 0.57 mass％ .