To provide a large pumping force, provide uniform pumping, and prevent freezing in winter by providing a container having an inlet port at a lower part of liquid and a discharge port at an upper part, and providing a liquid heating part having a contact surface with the liquid, so the contact surface is used as a boiling acceleration surface.

A container 1 is formed of a copper alloy pipe, a boiling acceleration surface 3 is formed along the whole surface of an inner surface at a part except for a joint part provided at a lower part to get in contact with liquid in the container 1. A lower part inlet port 16 and an upper part discharge port 17 are respectively provided at both of upper and lower end parts of the container 1, and flanges for joint are respectively provided on them. In addition, for forming part of a heating part 5 by the boiling acceleration surface 3, a heating wire 8 is wound through an insulation layer 7 of the container 1. In addition, it is covered with heat insulation material 9, and the outermost surface is sealed with a case 10. This boiling acceleration surface 3 is produced by applying grooving work to an inner surface of the pipe at a pitch of about 1mm and a depth of about 0.5mm, and appling lancet work of pressing a jig to the inner surface for crushing groove head parts.