PURPOSE: To prevent the oxidation of a bond coat layer and the main body of engine parts and to prolong the service life of a coating layer by laminating the surface of a top coat layer formed on the surface of the main bode with a seal coat layer preventing the diffusion of oxygen into the bond coat layer.

CONSTITUTION: On the surface of the main body 1a of a turbine blade 1, a bond coat layer 2 constituted of an Ni-base alloy or a Co alloy is formed by thermal spraying. The surface of the bond coat layer 2 is laminated with a top coat layer 3 constituted of zirconia series ceramics by thermal spraying. The bond coat layer 2 is formed for increasing the adhesion to the top coat layer 3, and the top coat layer 3 protects the surface of the turbine blade from heat. On the surface of the top coat layer 3, a seal coat layer 4 constituted of alumina, silica, zircon or a mixture thereof is formed by coating. The seal coat layer 4 prevents oxygen from reaching the bond coat layer 2 and the main body 1a of the turbine blade via the top coat layer 3.