Provided are a magnetic coupling as an axial bearing including a driven magnet (11B3) that is a permanent magnet provided to a rotating body (11) inside a casing (12) and a drive magnet (23A) that is a permanent magnet placed face to face with the driven magnet in a radial direction of the rotating body outside the casing to be magnetically coupled with the driven magnet, a driving motor (22) that rotatably drives the drive magnet about an axis (P) of the rotating body, a radial bearing that is a dynamic bearing having annular bearing surfaces (12B1, 11B1) centering on the axis on an inner wall of the casing and the rotating body, each of the annular bearing surfaces being arranged with a gap between the drive magnet and the driven magnet in the radial direction of the rotating body, and a closed impeller (11A) including a front shroud (11A1) arranged on a front side in the axis direction in the rotating body, a rear shroud (11A2) arranged on a rear side in the axis direction of the front shroud, and a vane (11A3) arranged between the front shroud and the rear shroud.
