A steam turbine blade includes a coating film formed at least a portion of a surface of the steam turbine blade, the coating film containing a ceramic matrix and nanosheet particles dispersed in the ceramic matrix. The steam turbine blade is employed as one of stator blades or one of rotor blades in a steam turbine. The steam turbine includes a turbine rotor, the rotor blades implanted in the turbine rotor, the stator blades provided in an upstream side of the corresponding rotor blades, and a turbine casing supporting the stator blades and accommodating turbine rotor, the rotor blades and the stator blades. The steam turbine is also configured such that the rotor blades are paired with the corresponding stator blades to form turbine stages arranged in an axial direction of the turbine rotor, thereby forming steam paths.