PURPOSE: To produce an immobilized enzyme in high immobilization ratio, by immobilizing an enzyme through a spacer consisting of a chain compound containing epoxy groups at both end groups to a carrier.
CONSTITUTION: Silica gel is treated with an acid, etc., to produce an amino group-containing carrier to which amino group(-NH2) is introduced. The carrier is blended with a chain compound such as ethylene glycol diglycidyl ether containing epoxy groups at both ends and the blend is stirred in water adjusted to pH 9W10 for about 4hr to give an epoxy carrier by covalent bond through the amino group and the epoxy group. An enzyme (e.g. glucose oxidase) is added to the enzyme, shaked in water adjusted to a pH range stable to the enzyme to produce an immobilized enzyme by covalent bond through the second epoxy group. The immobilized enzyme has improved enzyme manifestation activity.