TGH is a high performance growth chamber which can practice feedback control of light intensity in artificial light condition. Near-natural light condition is made by using metal halide lamp (Sunshine Ace) which is for plant growth. It is possible to make over 100,000 lux high light intensity, and to control 60-100% stepless continuous dimming. Furthermore user can examin different temperature, humidity, CO2 concentration and light intensity consitions. Each sensors, CO2 control system, and control panel (touch panel) is included as standard.