Provided is a pump that includes an annular molded stator having a substrate mounted with a Hall element and that includes a rotor having an annular rotor unit rotatably housed in a cup-shaped partition component, with one end thereof in an axial direction facing the Hall element and the other end thereof in the axial direction provided with an impeller attachment unit. The rotor unit includes a resin magnet, a sleeve bearing, and a resin portion. The resin magnet includes a rotor-position detecting magnetic-pole portion protruding axially with a predetermined height in an annular shape having a predetermined width in a radial direction on an outer periphery of an end face opposite to the Hall element. The rotor-position detecting magnetic-pole portion includes a plurality of arc-shaped notches on the same circumference on an inner diameter side thereof.