To increase economical efficiency, prevent the leakage of liquid, and prevent the freezing of flushing water in the winter season by incorporating an accumulator integrally with a pump without manufacturing the accumulator separately, and thereby increasing the smoothing action and force accumulating action.

On the downstream end part of an electromagnetic pump which performs pumping operation in cooperation with the volume change due to the operation of the electromagnetic pump 21 fitted in so that it can freely slide and reciprocate, and both suction and discharge-check valves, an operating diaphragm 7 is arranged to receive direct dynamic pressure, and a cylindrical elastic body 6 having a cavity part 9 as an air cushion is provided behind the pressure receiving surface of the operating diaphragm. Between the collar part of the peripheral edge of the lower end of a cap 5 surrounding the cavity part and the elastic body, and the flange part of a discharge joint part 11, an accumulator 3 for closely holding the peripheral end part of the outer edge of the operating diaphragm 7, is arranged on the discharge side of the pump so that it is incorporated integrally with the pump.