PURPOSE: An enzyme is immobilized on a carrier that is made by forming and sintering a mixture of specific amounts of fine glass beads and a borosilicate glass powder and the change in the product of the enzymatic reaction is measured.

CONSTITUTION: Fine glass beads (100pts.wt.) is mixed with a borosilicate glass powder (10W70pts.wt.) and the mixture is formed and sintered to form a carrier for immobilizing an enzyme. Then, an enzyme is immobilized on the carrier. The cell 2 is placed on the stirrer and the stirring bar 5 and stirring frame 6 are set in the cell 2. Further, the carrier supporter 4 having holes on the side wall is placed on the frame 6. The carrier 1 supporting enzyme is placed on the supporter 4 and the substrate 3 is poured in. The whole parts are placed in the chamber 8 and the thermostat cell holder 11 is fitted on the outer surface of the cell 2. A beam is introduced through the opening 9 into the chamber 8 and the absorption change of the light transmitting through the substrate 3 is measured with the receiver 10 and recorded.