Manganese peroxidase (MnP) from Phlebia radiata and glucose oxidase from Aspergillus niger were co-immobilized on porous silica beads. Immobilization of both enzymes on the same carrier provided an integrated system in which H2O2 required by MnP was produced by glucose oxidase. The immobilization process resulted in a decrease of both enzymatic activities and substrate affinities. However, immobilization improved the stability of MnP against H2O2 or high pH, as well as the storage stability of this enzyme.