The climate of stall significantly influences on animal production ability. High concentration of ammonia gas, $CO_2$ and lots of dust are found in modern densely raising stall system, as results, they provide a negative influence on animal and farmer health, and production ability. Therefore, it is necessary to keep clean the inside air of stall to increase the productivity. An air cleaner of wet type, consisting of a fan, a motor, rotating discs, a dust collector, a water bowl, an ozone generator etc, has been developed to clean the stall air. The work principle is that the inside air is sucked through the fan, and the rotating discs make water into fineness spray and blow into the stall. The rest water flows down to the dust collector. In the present study, we measured the dust, ammonia gas, odor, temperature and humidity in a swine stall that were installed two wet air cleaners with 700 fattening swine with On-mode and Off-mode of wet air cleaners. The dust measure was divided into 3 categories, TSP, $PM_{10}$, and $PM_{2.5}$. In summer, the TSP in on-mode were maximum $0.259mg/m^3$ and minimum $0.128mg/m^3$, and the average was $0.195mg/m^3$. These are comparable to the data from Off-mode stall that maximum $0.308mg/m^3$, minimum $0.139mg/m^3$, and average $0.277mg/m^3$. However, $PM_{10}$ and $PM_{2.5}$ showed any significant differences between the tests. The concentrations of ammonia gas in Off-mode stall were maximum 13.8 ppm and minimum 5.9 ppm, and the average was 8.47 ppm. However in On-mode stall the ammonia gas concentrations were maximum 10.5 ppm and minimum 5.5 ppm, and the average was 7.63 ppm. The concentration of ammonia gas in On-mode was 10% in average lower than off-mode stall. Odor was measured by olfactometer. In the Off-mode stall, the odor unit were maximum 420 $Ou/m^3$ and minimum $300;OU/m^3$, and the average was $367;OU/m^3$, but in the On-mode stall the odor unit were maximum $330;OU/m^3$ and minimum $210;OU/m^3$, and the average was $253;OU/m^3$. Odor removal efficiency was about 31% in On-mode stall.