An enzyme-fixed bioreactor, including a reaction column, enzyme-fixed catalyst particles uniformly and densely filled in the reaction column, the catalyst particles being composed of carrier sepiolite particles consisting essentially of sepiolite and an enzyme carried on the surface of the carrier sepiolite particles. The bioreactor has stable heat resistant and chemical properties, high productivity, and is economically superior to prior art, without fear of destruction of the catalyst, short path, and clogging in the reaction column.