The dual-stage positioning system technology for hard disk drives is one of the most important technologies for the fast and precise positioning of the magnetic head and the wide servo bandwidth. This paper describes a prototype of the electromagnetic micro actuator for dual-stage positioning. It is composed of a movable part with a yoke supported by the cross-shaped spring and the four micro coils. The driving force of this actuator is the electromagnetic force generated by those coils. The displacement was 3.2 μm at the frequency of 2 kHz with the applied voltage of 2.1 V. The linearity between the coil current and the displacement was fairly good by the differential current driving method. The first and second resonant frequency were 580 Hz and 20 kHz respectively.