Indoor air quality is a major concern to office room because it can impact directly from pollutants and risk of infection in the office. This survey study of Carbon dioxide concentration and ventilation in office environment during COVID-19 situation aim to determine CO₂ concentration and the ventilation in a closed office room and turning on the air conditioner during working and to compare the carbon dioxide concentration in the office room at different time. The samples were collected in 5 office rooms. Parameters were measured CO₂ concentration, relative humidity, wind speed, and temperature. The data were analyzed by using pair t-test.

         The results found that the temperature, relative humidity and wind speed value in almost room still in the guideline. In addition, CO₂ concentration of office rooms during working time in the Faculty of Public Health, Faculty of Allied Health Sciences, and Faculty of Education and during relaxing time in the Faculty of Allied Health Sciences and Faculty of Education exceed slightly the guideline. CO₂ concentration in all office room during working time was higher than the during time statistically significant at the 0.05 level which CO₂ concentration can indicated for ventilation assessment