The objective of this study is to evaluate VOC removal performance of an air cleaner based on the adsorption/desorption effect of adsorptive materials by experiments, and to examine the possibility to control indoor air quality by the air cleaner. The design of the air cleaner and the mechanism of shifting modes, adsorption and desorption, were improved for practical use. The improved system consists of two sorption units, ducts, two fans and a controller to change the mode. Natural zeolite was used as adsorptive material, and a large chamber, a capacity of 18.27m³, was used to investigate VOC removal performance of the improved air cleaner. Toluene and formaldehyde were used as pollutant sources and were continuously emitted into the test chamber. The experiments were conducted under the different operation modes, room air temperature, and relative humidity. Also, the removal performance for the long time operation mode was examined. As a result of experiments, the removal performance for formaldehyde under the condition of air temperature 15°C, relative humidity 25% and operation time 6 hours for one cycle mode showed high efficiency 50 to 80%. However the removal performance for formaldehyde under the high relative humidity 75% was low 0 to 5%. On the other hand, the performance for toluene showed the similar tendency as that for formaldehyde. Although the performance of the air cleaner for formaldehyde and toluene had no dependency on air temperature, the performance was strongly affected by the relative humidity.