Cellulase was immobilized on aluminium oxide beads with a polymer matrix by radiation polymerization at low temperature using various monomers. The optimum conditions for the preparation of the immobilized enzyme beads were obtained, and the characteristics of the immobilized enzyme beads investigated by repeated batch enzyme reactions. The cellulose component of chaff, pretreated by electron beam irradiation and subsequent pulverization, was effectively hydrolysed by the immobilized enzyme beads, in which the conversion (hydrolysis) yield in the repeated batch enzyme reactions with 10% chaff slurry was 53%.