The different ratio of food waste and sludge shows the significant results to the methane gas production where Mixture 2 shows the best results compare to the other mixure. Mixture 2 with the ratio 1:2 (1 kg food waste: 2 kg sludge) shows that from the 4 days operations the methane gas production increased gradually from 15 to 49% and after obtained the optimum level it drop until 23% .