Seal structure and the turbine

PROBLEM TO BE SOLVED: To provide a seal structure and the like capable of suppressing leakage of leaking fluid such as steam.SOLUTION: A seal structure 30 of a steam turbine 1 for sealing leaking steam flowing in a clearance gap between a rotor 12 and a casing 10, includes a plurality of seal fins 42 projecting from a ring body 41 fixed to the casing 10 toward a rotor 12 side, and disposed in an axial direction of the rotor 12, a plurality of step faces 51 disposed on the rotor 12 and opposed to the plurality of seal fins 42, and steps 33 in which step portions 53 are by riser faces 52 respectively formed between the adjacent step faces 51. The plurality of seal fins 42 are inclined to an upstream side in a leaking steam circulation direction from a ring body 41 side toward a tip portion with respect to a radial direction of the rotor 12, and corner portions formed by each of the seal fins 42 and the ring body 41 have curved faces.SELECTED DRAWING: Figure 2