PURPOSE: To send the corrosive liquid under pressure and reduce abrasion by housing an impeller consisting of screw centrifugal blades into a partitioning wall inside a ceramic body and revolving the impeller by the outside driving magnets.

CONSTITUTION: An impeller 1 consisting of female screw-shaped screw centrifugal blades 1a is housed in a partitioning wall 8, inside a nearly cylindrical ceramic body. The impeller 1 is axially supported in turnable ways by a shaft 3 fixed onto a pack casing 2 and a suction sleeve 4 extended from a suction inlet 9. Magnetic bodies 5 and 6 are arranged on the impeller 1, and liquid is sent under pressure by revolving the impeller 1 by the magnetic action supplied from the outside of the partitioning wall 8. Therefore, even the corrosive liquid can be sent under pressure, and abrasion can be reduced, and the use for a long period is permitted.