In this study, hydrogen sulfide ($H_2S$), ammonia ($NH_3$), and benzene, which represent the major odor from a natural leather process plant, were removed using a fluidized bed bioreactor and biofilter including Thiobacillus sp. IW and a MY microbial consortium. The critical removal rate was $12g m^{-3}h^{-1};for;H_2S,;11g m^{-3}h^{-1};for;NH_3;and;28 g m^{-3}h^{-1}$ for benzene by the fluidized bed bioreactor, and $8.5g m^{-3}h^{-1};for;H_2S;7g m^{-3}h^{-1};for;NH_3,;and;25 g m^{-3}h^{-1}$ for benzene in the biofilter. The average removal efficiency of $H_2S$, $NH_3$, and benzene by continuous operation for over 30 days with the fluidized bed bioreactor was $95{pm}3\%,;99{pm}1\%,;and;98{pm}5\%$, respectively, whereas that with the biofilter was $96{pm}4\%,;95{pm}4\%,;and;97{pm}3\%$, respectively. Therefore, the critical removal rate of $H_2S$, $NH_3$, and benzene was higher in the fluidized bed bioreactor, whereas the removal efficiency on the continuous operation was similar in both bioreactors.