This study was to optimize the pH for immobilization as well as for repeated saccharification of dextrinized starch by physically immobilized amyloglucosidase on DEAE‐cellulose. Immobilization activity yield for physical immobilization of amyloglucosidase on DEAE‐cellulose was high at neutral pH values. Activity of immobilized amyloglucosidase increased as pH decreased and was high at pH 4.0 under our experimental conditions. However, for the repeated batchwise saccharification of dextrinized starch, pH 4.5 was optimal as both degree of saccharification (85%) and enzyme retentivity(72%) of immobilized enzyme were high at the end of third cycle.