When the alternating current is applied to the electromagnet as in Figure 3 shown opposite, the actuating rod moves first in the arrow direction shown in Fig. 3A, and then in the arrow direction shown in Fig. 3B by the magnetic attraction and repellent forces exerted between the electromagnet and the permanent magnets attached to the rod. The rod vibrates at the same frequency as that of the power supply and changes the volume of the space enclosed between the casing and the diaphragm. Thus, air intake, compression and exhaust can be performed through the valves.