To provide a monoclonal antibody, etc., against chondroitin sulfate lyase II for the production of a chondroitinase ABC fraction having ultra-high purity.

The invention provides a monoclonal antibody specifically binding to chondroitin sulfate lyase II, a hybridoma strain producing the antibody, a method for the determination of chondroitin sulfate lyase II using the antibody, and a method for producing a chondroitinase ABC fraction having the following properties (1) and (2) by using a step to detect the chondroitin sulfate lyase II by the determination method. (1) The chondroitin sulfate lyase II is not detected by an immunoassay method using an antibody specifically binding to the chondroitin sulfate lyase II and (2) the peak of chondroitin sulfate lyase II is not detected by high speed liquid chromatography.