In this study, we choose an apartment house that has a ventilation system contained with CO<SUB>2</SUB> sensors. The ventilation system runs on above 1,000 ppm of CO<SUB>2</SUB> in indoor air. The control performance and electrical energy usage of CO<SUB>2</SUB> sensor contained ventilation system has been monitored for one month and also analyzed. As a result, the average CO<SUB>2</SUB> concentration in nursery room is 782 ppm, at ventilated home as 1,563 ppm at non-ventilated home. And electricity consumption by ventilation was 13.3 kWh. This study can be utilized as a basis for extension of CO<SUB>2</SUB> sensor contained ventilation system application and encouraged for the use of conventional ventilation systems.