Steam turbine

A steam turbine that can effectively operate with the steam at the higher temperatures, while maintaining the strength of turbine constituent components despite the high steam temperature of the steam provided. The steam turbine comprises a casing (32,33), a rotor (34), a plurality of turbine stages (28), a steam pass, a nozzle box (31), and a cover plate (41). The rotor (34) is rotatably installed in the casing (32,33). The turbine stages (28) are disposed in the turbine, at least one of the turbine stages (28) including a turbine nozzle (29) and including a moving blade (30) that is fixed to the rotor (34). The steam pass including the at least one turbine stage (28). The nozzle box (31) is placed in a space between the casing (32,33) and the rotor (34) for providing a heated steam into the steam pass. The cover plate (41) is arranged along aoutside of the nozzle box (31).