A steam turbine pipe 1 in an embodiment is a steam turbine pipe in a steam turbine facility. The steam turbine pipe 1 includes: a steam passage 30a that leads steam from a boiler to a steam turbine; and a branching passage 40 that branches off from the steam passage 30a. The steam turbine pipe 1 further includes: a shutoff valve 32 that intervenes in the branching passage 40; and a reduced pipe part 31b that is provided at a part of the branching passage 40 between the steam passage 30a and the shutoff valve 32 and made by reducing a passage cross section of the branching passage 40.
