A multi-functional indoor smog chamber was designed and evaluated to investigate photochemical or water vapor reaction mechanisms of air pollutants. Various smog chamber experiments could be conducted using ambient air or purified air in this smog chamber. The smog chamber consisted of a housing, a Teflon bag, blacklights, injection ports, sampling ports, and utility facilities. The characteristics of light source, the wall losses of air pollutants, and the quality of purified air were experimentally investigated. The maximum NO$_2$ photolysis rate was 1.10 min$^{-1}$ . In a 2.5-m$^3$ Teflon bag, the wall losses of ambient $O_3$, NO, and NO$_2$ were 1.2~2.4$ imes$10$^{-3}$ min$^{-1}$ , 0.7~2.0$ imes$10$^{-3}$ min$^{-1}$ , and 0.4~2.0$ imes$10$^{-3}$ min$^{-1}$ , respectively. The wall loss of ambient particles ranging 0.05 to 0.2 ${mu}{ extrm}{m}$ was 1.8~5.4$ imes$10$^{-3}$ min$^{-1}$ , which was slightly higher than those of ambient gaseous species. The purified air supply system provided high quality of air with NO$_{x}$ < 1 ppb, and total hydrocarbons < 5 ppb.b.