Provided is a process for preparing an immobilized enzyme, which comprises the steps of immobilizing an enzyme used for decomposing oil & fat on a carrier, by adsorption, without drying, bringing the immobilized enzyme into contact with a fatty acid triglyceride or fatty acid partial glyceride, or mixtures thereof, and adjusting the moisture content of the enzyme to 5% to 50% by weight based on the weight of the carrier, wherein the enzyme is used for esterification.