In this study, amenity evaluation technique for indoor air quality in the underground space was developed and evaluated real-time amenity by utilizing real-time sensor monitoring system equipped with the technique. The factors used for amenity evaluation were PMV value, VOCs, illumination, PM10 and CO2. The amenity value with 60 percent represents the environmental standards of subjected factors. Based on the field survey using the monitoring system developed under this study, the amenity values of CO2 whose environmental standard is 1,000ppm were 97% for 400ppm and 26% for 1,100ppm, respectively. That of PM10 having 150㎍/㎥ as an environmental standard were 99% for 25㎍/㎥ and 80% for 100㎍/㎥. Evaluated amenity based on VOCs concentration at the subjected areas was in bad condition. And those for PM10 and CO2 were dependant on the floating population. From the results of this study, the real-time sensor monitoring system installed with the amenity evaluation technique could be a practical tool to evaluate indoor air quality to manage air quality of underground spaces like subway station. New amenity assessment technique using a real-time sensor monitoring of indoor air quality as well as physical environmental properties was developed in this study. The concentrations of CO2, PM10, VOCs were considered as new parameters to analyze the indoor air quality and they are included in an amenity assessment program of indoor area. We found that the new method is better to express the amenity degree of residents through field tests than conventional thermal comfort technique. Keywords : Indoor Air Quality, Amenity, Sensor, Monitor