An electromagnetic vibrating diaphragm pump capable of increasing pump efficiency by increasing the vibration amplitude of the vibration of diaphragms even when the pressure inside a compression chamber is high. Diaphragms are fixed to both end portions of an oscillator having magnets. AC driven electromagnets are provided in a manner to face the magnets of the oscillator. A frame adhered to the outer peripheries of the diaphragms covers the electromagnet side, and pump casings cover the opposite sides. The pump casing includes a compression chamber adjacent to the diaphragm, a suction chamber connected to the compression chamber via a suction valve and an exhaust chamber connected to the compression chamber via an exhaust valve, the suction chamber or the exhaust chamber being connected to the frame via a continuous hole.