Since its establishment in 1944, it has been a manufacturer of comprehensive measurement equipment that provides various analytical instruments with "water, air, medical care, and gas" as its pillars. There are 11 business outlets and 4 group companies in Japan. Among them, Yamagata Toa DKK Co., Ltd. is the main production plant of Toa DKK, and has a high-efficiency production system with its own production equipment. Led by China, it develops, produces, and sells measuring machines with the theme of environmental protection for the world.