PURPOSE: To reduce a capacity between electrodes so as to enhance a high frequency characteristic by etching a material for electrodes by the use of metal films developed at the tip end portions of the material for the electrodes as masks.
CONSTITUTION: A tungsten layer 1 is etched in two directions slantwise with respect to the main surface of a base, thus obtaining a pair of grooves 2, 3. Portions of the layer 1 divided by the grooves 2, 3 serve as an emitter electrode 4, a collector 5 and a pair of base electrodes 6. Cesium films 8 made of metal functioning as a mask are formed at the tip end portions 4a, 5a, 6a of the electrodes 4, 5, 6. Isotropic dry-etching is applied to the cesium film 8 as the mask, and only tungsten of a material for the electrode is selectively removed. At this time, the grooves 2, 3 are extended in portions other than the films 8 so that recess portions 9 are formed on base end sides of the electrodes, and accordingly, distances between the electrodes 4, 6 and 5, 6 are enlarged in portions other than the films 8. Consequently, a capacity between the electrodes can be reduced, thus enhancing a high frequency characteristic of a transistor.