The author summarizes technical development of mass production of high quality quartz crystals in Toyo Communication Equipment Co. Ltd where he worked since 60 years ago. In the project, reactors have been increased to volume of 650 mmφ x 14 m long with overcome of many problems such as sealing structure and temperature control system. Episodes on seed crystals, high quality crystals for optical applications, colored crystals, accidents and awards are also presented.
