We investigated the air pollution in the student smoking hall from Feburary 1st in the winter season, and during 8 days in the middle of April in the spring season. The student smoking hall was in an open, draughty location. Moreover, the concentration of pollutants were measured in three time periods: break, lecture and lunch times. The pollutants measured were nitrogen monoxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2), suspended particulate matter (SPM) and polynuclear aromatic hydrocarbon (PAH). The concentrations of pollutants measured during the break times were of a relatively higher level than those during the lecture and lunch times. However, the concentration of pollutants were not influenced by ventilation operation in the smoking hall, which is not a closed place. SPM and CO2 concentrations during the break time were instantaneously investigated above Building Sanitation Standards Management, Japan (SPM: 0.15mg/m3, CO2: 1, 000ppm). Especially, the SPM concentration was recognized to be strongly influenced by tobacco smoke.