In a magnetically levitated pump, an impeller-side ferromagnetic body
(second ferromagnetic body) provided on a circumferential surface of an
impeller facing a casing unit on the side of a position sensor and a
casing-side ferromagnetic body (third ferromagnetic body) opposite to the
impeller-side ferromagnetic body (second ferromagnetic body) to attract
the impeller toward the casing unit on the side of the position sensor
are adapted to have opposite portions of mutually different shapes, so
that the maximum required attractive force of an electro-magnet for
magnetic bearing is suppressed and length of the electro-magnet for
magnetic bearing is made shorter.