We have constructed a novel glucose sensor in which the enzyme is immobilized on a plasma-polymerized ®lm deposited on a patterned miniature electrode. The ®lms, which are formed by the glow discharge of a plasma of organic vapors, are extremely thin, adhere strongly to substrates, are mechanically and chemically stable, and are deposited in a dry process. As most miniature devices are fabricated using semiconductor process techniques, i.e., dry processes, the plasma technique has enormous advantages for the fabrication of microsensors. The samples were measured using amperometric methods and this sensor was effective for glucose concentrations ranging from 0 to 30 mM with a detection limit of 1 mM. The sensor showed a short response time of 12 seconds.