Mitsubishi Gas Chemical Co.,Inc.[MGC] has developed a new MMA manufacturing process based on acetone cyanohydrin that we call New ACH process. The new process eliminates by production of ammonium bisufate(NH4HSO4), as it does not use sulfuric acid. Also, it is little restricted by location since it uses very common chemicals such as methanol and acetone as main raw materials. The MMA production plant utilizing this new technology was built in NIIGATA in the spring of 1997, and after about half a year of test run, is presently being operated commercially.