Electrochemical incorporation of enzyme molecules into the growing matrix of platinum black particles is employed for the microfabrication of the enzyme electrode. Two electrochemical processes, i.e., electrochemical adsorption of enzyme molecules and electrolytic (reductive) deposition of metallic microparticles from its complex compound, are simultaneously carried out by using a microelectrode whose diameter is below 50 μm. A glucose sensor, a glucose oxidase-incorporated microelectrode, demonstrates high performance with high sensitivity and fast responsiveness.