Air pollution becomes a significant problem that can threaten human life. Many human activities that cause air pollution. In this final project was made a prototype cleaning and monitoring carbon monoxide gas in the enclosed space based of microcontroller ATMega8535. The method used is to process data detected by carbon monoxide gas sensor TGS 2442, then issued a voice output , led , display on lcd and turning the fan to remove the carbon monoxide gas. comparison of the value changes on the sensor , will be processed by the microcontroller ATMega8535 then be entered in the system to control a DC fan performance in response to the air exhaust ventilation of the room . The results obtained from the implementation of this thesis is can detect the smoke or carbon monoxide gas in the space simulator of smoke pollution and CO from 0 % to 100 % and the pollution can be reduced by controlling the air flow in ventilation of the room . With the design tool is expected to help regulate air circulation, detect the dangers of carbon monoxide in cigarette smoke in a room , and reduce the dangers posed to human health .