Tomioka Silk Mill is the symbol of "Silk Country" Gunma. It was the first official silk reeling factory established by the Meiji government in 1872. Through it was disposed to the private company in 1893, Tomioka Silk Mill kept its operation as silk reeling factory for 115 years, until the closedown in 1987. Through the introduction of modern silk reeling machines from Western countries and French instructors to teach local female operators, the mill made the mass production of good quality raw silk possible in Japan.
Tomioka Silk Mill, with other related sites of silk industry in the prefecture, aims to be registered as a world heritage in 2014. Tomioka Silk Mill is worth to be preserved as a heritage because: (1) it contributed greatly to Japan’s modernization through the improvement of silk industry, and (2) the main buildings of the mill still preserved in excellent condition in situ.