In the redesign of the fumigation room in the Historical Institute of Saitama, Japan, the room was equipped with air tight doors with Neoprene packings and several valves including a gas concentration measurement valve. In addition, the fumigation chamber had a residual gas suction unit (of cartridge type), evaporator, chamber heating system, highly sensitive alarm system, control panel and other features. Fumigatory effectiveness of the room thus completed was checked by using fumigation test samples. The results showed the fumigation chamber to be 100% effective in destroying insect pests and fungi. -- AATA