The turbo machine includes a rotor 1 with a rotating shaft 3, a stator 2 enclosing the rotor 1 and a sealing device 20 installed in a clearance passage defined between the rotor 1 and the stator 2, the sealing device 20 controlling a leakage flow from the clearance passage B. The sealing device 20 includes a plurality of sealing fins 24 disposed on at least one of the rotor 1 and the stator 2, and arranged in an axial direction of the rotor 1. The sealing device 20 further includes at least one deceleration controlling member 25 provided on the rotational side. The deceleration controlling member 25 projects toward a chamber 30 defined between the sealing fins 24 and is configured to control a reduction in the velocity of the leakage flow B in the chamber 30 in the rotational direction of the rotor 1.