In a rotor portion, a magnet formed in a cylindrical shape, a first magnet holder that holds an impeller-attachment-portion-side end portion of the magnet, a second magnet holder that holds a magnetic-pole-position-detection-element-side end portion of the magnet, a back yoke disposed inside the magnet, a sleeve bearing disposed inside the back yoke, and a position detection magnet that is provided on a surface of the second magnet holder at a side opposite to the side at which the magnet is attached and allows a magnetic flux of the position detection magnet to be detected by the magnetic-pole-position detection element are assembled integrally together with a thermoplastic resin, and the impeller attachment portion is formed of the thermoplastic resin.