To protect a cable of a motor from entwinding of foreign materials and disconnect the cable.

An impeller 11 rotated by a motor 20 is arranged inside a pump casing provided on a lower side of the motor 20. A immersion sensing mechanism 30 is arranged on the motor 20. The immersion sensing mechanism 30 has a sleeve 31 in a bent state which is arranged on the oil casing 25 with a water-light condition. An electrode bar 32 is horizontally supported to the side portion of a horizontal part of the sleeve 31 so as to be projected into the oil casing 25. An end of a cable 33 electrically connected to the electrode bar 32 inside the sleeve 31 is supported thereto. The cable 33 is extracted upward from the sleeve 31 along an outer peripheral surface of the motor 20.