In this study, experiments were conducted to investigate the production of ammonia gas from stripping of ammonium ion content as a contaminant in municipal solid waste (MSW) leachate by using anaerobic digestion process. Batch type of reactor was setup by introduce charcoal inoculums with sewage based bacteria as a bio-filter and were conducted at room temperature varying from 26 to 36 0C with a fixed hydraulic retention time (HRT) of 5 days. The digester was operated at different leachate feeding rates of 20, 40, 60, 80, and 100 ml/min. Before that the ammonium concentration in the leachate were fixed at around 500 mg/l to ensure the standard level of ammonium ion at early of each bath of the experiment, meanwhile the lowest ammonium ion concentration level after stripping process reduce to 80 mg/l and the reduction percentages of the ion is around 84%. Maximum ammonia gas produce from this experiment was around 0.014L.