The quality of indoor air in educational institutions is a critical determinant of the health and well-being of students. The purpose of the study was indoor air quality monitoring carried out for different age groups of students in grades IV-VIII or college classrooms (students used the classroom according to the schedule, the same group uses the room for up to 2 classes), I-III (students stay in the classroom for all classes, leaving only during breaks), kindergarten "0" (students are practically in one and the same room all day). The individual measurements included measurement of CO2 concentration, concentration of PM2.5 and PM10 particles, formaldehyde, volatile organic compounds (VOCs), along with monitoring of changes in temperature and humidity in the classroom. The results indicate that children are exposed to elevated levels of these pollutants for a significant portion of their school day, which can have implications for their health and well-being. The findings reveal significant deviations from recommended levels, emphasizing the need for improved ventilation and monitoring practices.