In this paper, we studied the efficiency of reducing sulfur inhibition during anaerobic digestion using biochar. The study was conducted using a batch test called the biochemical methane potential test in which various concentrations of Na2S were injected to determine the effects of sulfur. This experiment used leached food wastewater as the feedstock, and the composition of the experiment was divided into three sets; In Set 1, only Na2S was injected except for control, based on sulfur concentration (20-1,000 mg/L). In Set 2, biochar (BC, 5 g/L) were additionally injected to the Set 1 conditions. For comparison, FeCl<sub>3</sub> (24 g/ L) was injected together with Na<sub>2</sub>S in Set 3. The experiment indicated that overall the concentration of H<sub>2</sub>S in the generated biogas was significantly lower than that of other sets in Set 3 (injected with FeCl<sub>3</sub>). Furthermore, the concentration of H2S in Set 2 (injected with biochar) was found to be lower than that of Set 1 in the low-concentration range of Na<sub>2</sub>S. However, there was no significant difference from Set 1 in the high concentration range of Na<sub>2</sub>S. This result indicates that biochar can reduce the inhibition of sulfur; however, the efficiency decreases as the concentration increases. Furthermore, Set 3 yielded lower methane compared to the other sets, where the lowest biogas yield and methane yield were found to be 200+Fe in Set 3 as 0.046 m<sup>3</sup>/kgVS and 0.021 m<sup>3</sup>/kgVS, respectively. On the other hand, the highest biogas yield and methane yield were found to be 25+BC in Set 2 as 0.308 m<sup>3</sup>/kgVS and 0.166 m<sup>3</sup>/kgVS, respectively. This result indicates that Fe can reduce the effects of sulfur; however, it cannot enhance the efficiency of biogas production. Meanwhile, biochar has been seen to enhance both sulfur control and biogas production efficiency and hence can be used as a valuable material.