A novel method has been developed for producing platinum silicide gate electrodes with submicron width. A lateral chemical reaction of platinum with polycrystalline silicon at a step edge was used. The width of the wire is determined by the thickness of a sputtered metal layer. Wires with width between 35 and 300 nm have been produced. The method has been used for making long-channel field-effect transistors with good device properties. Some preliminary results of the study of the low-temperature electrical transport properties of inversion layers with width of 0.12 μm are reported.