PURPOSE: To return the fluid leaked from the gap between the end faces of adjacent shrouds to the stationary blade side and reduce it by slantly forming the gap between the end faces of adjacent shrouds so that the stationary blade side is located downstream the rotating direction.

CONSTITUTION: The gap between the end faces of adjacent shrouds 6 is slantly formed so that the stream inlet side of the shrouds 6 is located downstream the rotating direction of the shrouds 6. A groove X having the width (1) larger than the distance between the end faces of the shrouds 6 is slantly formed on the end face of the shroud 6. The end face of the shroud 6 provided with the groove X is machined into a step shape having heights t1, t2, and it is cut at the angle that a pumping action is generated in the rotating direction from the low pressure side to the high pressure side. The steam blown out from the limited gap between the end faces of the shrouds 6 is returned to the stationary blade 2a side at the inlet of steam and reduced by the pressure rise due to the pumping action, and the sealing performance between the shroud 6 and a flow guide 2b above the shroud 6 is improved.