This study aims to investigate the indoor air quality by analyzing $PM_{10}$ concentration and metallic elements collected from high school(classroom, science room, assembly room). $PM_{10}$ concentration of a classroom, a science room, and an assembly hall during the research period was 87.7 ${mu}g/m^3$, $75.3{mu}g/m^3$, $64.6{mu}g/m^3$, respectively. Si of $PM_{10}$ had highest concentration with 15,427 $ng/m^3$ followed by Na which had 7,205 $ng/m^3$, and the order was Si>Na>Ca>Mg>Fe>K in the classroom. $PM_{10}$ concentration of a classroom and a science room was each 104.8 ${mu}g/m^3$ and 75.3 ${mu}g/m^3$ during the semester and $PM_{10}$ concentration of a classroom and an assembly hall was each 80.9 ${mu}g/m^3$ and 64.6 ${mu}g/m^3$ during the summer vacation. Based on $PM_{10}$ and metallic concentration at a classroom on day of week, the concentration of Friday was highest with 112.0 ${mu}g/m^3$, and that of Monday was lowest with 65.3 ${mu}g/m^3$.