PURPOSE: To decrease the overhung length of a pump shaft so as to omit an underwater bearing and enable a pump to be suitably operated, by forming a suction flow path in a position higher than that of an impeller suction port from a pump suction port so that liquid, after flowing in an impeller and being pressurized, is allowed to flow toward a delivery port.

CONSTITUTION: Liquid in the inside of a tank 1, flowing upward from a suction port 10 in a suction passage 15 formed by an inner barrel 13 and an outer barrel 14 and changing its flow into the direction at a right angle with an axis by a baffle plate 16, is allowed to flow in a suction guide part 17 through an impeller 18 as a downward flow and reach a pump delivery port 11 through a guide vane 19. While an overflow nozzle 20, being provided in the upper part of the baffle plate 16, sets a free liquid level H.W.L. By such constitution, a circulating pump, whose weight and size can be decreased, enables an underwater bearing of troublesome maintenance to be omitted further its operation to be stably performed by reducing the overhung length of a pump shaft.