A turbine includes: a blade body having a blade provided at one of a rotor rotatably supported and a stator provided around the rotor and extending in a radial direction and a shroud extending in a circumferential direction at a tip portion in the radial direction of the blade; and an accommodating concave body provided at another one of the rotor and the stator, extending in the circumferential direction, accommodating the shroud with a gap interposed therebetween, and relatively rotating with respect to the blade body, wherein a leakage flow leaked from a main flow flowing along the blade flows into the gap; and wherein the shroud is provided with a guide curved surface formed between a peripheral surface facing the accommodating concave body and a trailing edge end portion formed closer to a main flow side in a downstream side of the leakage flow than the peripheral surface.