Recently Korean government introduced and strengthened the environmental polices to manage and enhance indoor air quality as a major assignment. As a result,“Indoor Air Quality Management Act”has been activated since May 2004. However, among many multi-usage facilities, the school environment has been excluded from such regulations. Thus, the purpose of this study is to survey indoor aerosol and CO2 concentrations in a university library which is one of major school facilities. Concentrations of PM10, PM2.5, and PM1 were intensively measured every 5 minute interval by means of a dust monitor with light-scattering principle. The mini-volume air samplers were used further to analyze inorganic elemental compositions of PM10 and to inter-compare with the dust monitor. Carbon dioxide was simultaneously monitored by a multi-gas monitor equipped with a non-dispersive infrared system. PM10 concentrations did not exceed the indoor air quality standard(150㎍/㎥) for all the sampling places. However, quick and steep increases of aerosol concentration were observed during the Asian Dust storm period. In addition, the concentration of PM10(74.1㎍/㎥) in the main university office was the highest among the entire sampling places. Although there was no specific pollution source in the library, the levels of aerosol and CO2 increased quickly due to various outdoor sources and human activities. The average CO2 concentration measured in three reading rooms, where ventilation was not fully operated, exceeded the indoor air quality standard of 1,000 ppm. Based on these case studies, effective management and reduction plans for indoor aerosol and CO2 were suggested for the large scale public buildings including university libraries. Keywords : Indoor Air Quality, PM10, PM2.5, PM1, CO2, Element