Chemical cleaning was investigated for a membrane bioreactor (MBR) treating restaurant wastewater. Test results showed that membrane foulants were comprised of inorganic and organic substances. Sparingly soluble salts containing Mg, Al, Ca, and Fe were the major components of the inorganic foulants, and protein was likely to be the organic foulant with high hydrophobicity. It was also found that the chemical cleaning could modify the contact angle of the membranes, and the membranes became more hydrophobic than the virgin membrane after chemical cleaning. 2% sulfuric acid, 3% sodium hydroxide, and 4% sodium hypochlorite with 66.0%, 59.0%, and 56.3% flux recovery efficiency showed better performance than others.