Restaurant liquid waste is rich in BOD5 dan COD and thus needs to be processed before being flown to environment. A study aims to reduce the BOD5 and COD in that waste by using the biofilter that was added with EM4 has been conducted in May-June 2019. A Completely Randomized Design (CRD) with 3 treatments, without EM4 (P0), addition of 7.5 ml (P1), 10 ml (P2) and 12.5 (P3) EM4 in the anaerobic.