This is a short history of Japanese watch industry after the second world war. In Japan, clock industry started in 1860s, and watch industry began in 1890s. Watch and clock industry developed rapidly, but in 1941 the second world war broke out, so that these industries were stopped for the munition production. Since the war, from 1945, these revived, then high quality and big quantity were required. I try to report of watch industry development, on products research and production technology.