PURPOSE: To control vibration and to reduce noises by holding both ends in the axial direction of the vibrating part with the elastic member which is fixed in the inside of the casing, and to make the pump itself smaller and lighter by making the outer casing serve both as a muffler and the outer casing.

CONSTITUTION: When AC power source is connected to the electromagnetic coil 16, the needle 19 is alternatively shifted in the axial direction by the alternation magnetic field to axially move the diaphragm 21 through the shaft 21. Therefore, the fluid is purified at the air filter 7 and sucked in through the suction pipe 5 and sent to the compressing chamber D through the penetrating ports A, B, the suction ports 22a, 22b, the suction chamber C, and the suction valves 26a, 26b to be compressed, and then delivered from the delivery port 4 through the delivery valves 27a, 27b and the chamber 29. In this case, the vibration in the axial direction accompanied by the movement of the needle 19 is controlled by the elastic members 10, 10 fitted between the side frames 12, 13 and the inside of the outer casing 1 to reduce noises.