A rotating machine includes a casing having a hollow shape; a rotator rotatably supported in the casing; a stator blade fixed to an inner peripheral portion of the casing; a rotor blade fixed to an outer peripheral portion of the rotator while being displaced from the stator blade in an axial direction of the rotator; a sealing device disposed between the inner peripheral portion of the casing and a tip of the rotor blade; a swirling flow generation chamber provided along a circumferential direction of the rotator on a downstream side of the sealing device in the casing in a fluid flow direction; and guiding members provided at predetermined intervals in the swirling flow generation chamber in the circumferential direction of the rotator. The guiding members each include a first guiding surface that is inclined in the circumferential direction with respect to the axial direction of the rotator.