A high accuracy indoor air quality monitor, which measure VOC. CO2, Temperature, Humidity and dust. Through large size of graphic LCD, it provides real-time monitoring and can transmit data wirelessly through built in ZigBee. After install indoor Watch (software), it enable to collect data at a long distance. Relay Contact make it possible to interwork with a ventilating system. It has been installed to measure Air quality of indoor or underground spaces like Factories, schools, Public places etc.