Abstract: A strain detector which is improved in corrosion resistance and moisture resistance and is high in reliability. The strain detector comprises a driven member, a magnetic shielding layer of a non-magnetic or diamagnetic material selectively formed on the driven member, a magnetic layer formed at a portion of the driven member at which the magnetic shielding layer is not formed, and a detecting coil provided corresponding to the magnetic layer. The magnetic layer may be formed in such a manner as to project from the driven member by selectively removing a surface of the driven member. Preferably, a protecting layer is formed on surfaces of the magnetic layer and the magnetic shielding layer. A process of producing such strain detector is also disclosed by which a magnetic shielding layer can be formed only at a required portion of a driven member readily in a short period of time.