An improved electromagnetic actuator which is provided with a coil (10) for impressing current, a magnet (20) which forms a magnetic circuit while keeping a magnetic gap (G) against a magnetic yoke (21), a diaphragm (11) which oscillates when a high-frequency current is impressed, and another diaphragm (22) which oscillates when a low-frequency current is impressed and wherein each section is housed in an enclosure (3) with the coil (10) being arranged in the magnetic gap (G). In one of the embodiments, a bottom plate composed of radially oriented magnets, diaphragms with a double-suspended structure, and a magnetic shield member is attached to the enclosure so as to suppress the leakage of magnetic fluxes from the enclosure and elastic packings (5 and 7) are put not only between the enclosure of the actuator and the housing case of portable electronic equipment, but also between the enclosure of the actuator and a mounting substrate so as to further improve the frequency characteristics of the actuator from the side of the mounting structure of the actuator.