2 increases and the pressure reduces and the formed pressure difference drives the sealing pads 38 between the air pump middle frame 37 and the air pump body 10 to move toward the left side the inlet hole of the air pump middle frame 37 is opened and the outlet holes on the air pump middle frame 37 are blocked both the inlet holes and the outlet hole of the air pump body 10 are opened and the second chamber a 2 inhales air through the inlet pipe 103 of the air pump body 10 that is to say in the one way valves formed by the air pump end cover 31 and the air pump middle frame cover 32 and by the air pump middle frame 37 and the air pump body 10 the inlet holes merely inhale air and the other outlet holes merely exhaust air so as to maintain the vacuum degree within the vacuum inner spaces as shown in fig2 in combination with fig8 the above motion process is the operation process of the first chamber and the second chamber formed on one side of the air pump body during one rotation of the motor at the same time another first chamber and another second chamber having the same structures and operating in the same manner are also formed on the other side of the air pump body as shown in fig2 when the air pump operates the motor rotates once and it drives each air pump soft gum membrane connected with the motor via a shaft to perform reciprocating movement in one round trip at the.