A steam turbine pipe 1 of an embodiment includes: an upper half side main steam pipe 11 that leads steam to a steam turbine; an upper half side main steam control valve 30 that intervenes in the upper half side main steam pipe 11; and a post-valve drain pipe 31 that is connected to the upper half side main steam control valve 30 and leads drain to an outside. The steam turbine pipe 1 further includes: a shut-off valve 32 that intervenes in the post-valve drain pipe 31; and a branching pipe 60 that makes the post-valve drain pipe 31 on the side closer to the upper half side main steam control valve 30 than is the shut-off valve 32 communicate with the upper half side main steam pipe 11 between the upper half side main steam control valve 30 and a high-pressure turbine 200.