PURPOSE: To increase the ability of a pump, by coupling the lower ends of a right and a left vibrator plates together by means of a connecting member so that the two vibrator plates are vibrated in the same direction while keeping a proper spacing from each other, and thereby causing vibration of the two vibrator plates at correct positions irrespective of the level of load acted to the pump.

CONSTITUTION: When Ac vibrated is applied to an AC electromagnet 7, vibrator plates 2a, 2b connected respectively to diaphragm pumps 5a, 5b and having permanent mangets 6a, 6b at their lower ends are vibrated in the same direction, so that the vibtation force is in creased as compared with that obtained when the two vibtator plates are vibrated in different directions. That is, the force exerted when the N-pole of the permanent magnet 6a is attracted by the S-pole of a core 14c of the AC electromagnet 7 and the force exerted when the S-pole of the permanent magnet 6a is attracted by the N-pole of a core 14b by the intermediary of a connecting member 11 are added together, so that a greater force is acted to the diaphragm 5a. As the result, it is enabled to increase the pump itself.