PURPOSE: To provide a manufacturing method which can prevent an increase in resistance of a channel layer made of compound semiconductor as a material with resist peeling solution and realize excellent element characteristics.

CONSTITUTION: A compound semiconductor layer (channel layer) 21 and a protective layer 22 formed of a silicon nitride film or a silicon oxide film are first sequentially laminated on a substrate 20. Then, a resist layer 23 is provided on a special region A to be a channel, and a protective layer 22a and a compound semiconductor layer 24 at both sides are removed. After the layer 23 is removed with a resist peeling solution, necessary parts of the layer 22 are sequentially removed to form a source electrode 27, a drain electrode 28 and a gate electrode 31.