In this study, the additional enzyme catalase is added to the bioselective membrane of the monoenzyme biosensor to improve the analytical characteristics of the biosensor. In this case, catalase is used to increase the saturate the biomembrane with oxygen, and, accordingly, facilitate the passage of the reaction catalyzed by enzymes of the oxidase class. A standard monoenzyme conductometric biosensor based on glucose oxidase for glucose determination and a new bi-enzyme biosensor based on glucose oxidase and catalase were compared. The optimal method of coimmobilization of enzymes on the surface of the conductometric transducer was investigated, as well as the dependence of the biosensor performance on the concentration of catalase in the bioselective membrane. The stability of the biosensor preparation procedure and the reproducibility of its results were verified. The analytical characteristics of the proposed bi-enzyme biosensor are compared with the monoenzyme biosensor. It is shown that the addition of catalase to the bioselective element of the biosensor as an additional enzyme significantly improves the analytical characteristics of the biosensor, including sensitivity, reproducibility of measurement results, and linear and dynamic ranges of operation. The developed method could be used in future to improve the parameters of other oxidase-based biosensors.