In conjunction with a magnetic disk drive unit comprising a voice coil motor (14), an arm (12) extending from the motor, a magnetic head actuator (2) mounted at a distal end of the arm, a suspension (16) coupled to the actuator, and a magnetic head slider mounted on the suspension at its distal end, the magnetic head actuator (2) comprises a stator section (30) secured to the arm distal end, an attachment section (18) secured to the arm distal end together with the stator section, micro-beams (20, 22) extending from the attachment section, a rotor section (24) supported for swing motion by the micro-beams, a permanent magnet (32) disposed in the stator section, and a coil (28) disposed in the rotor section. Electric current is conducted through the coil in the magnetic field created by the permanent magnet for causing the micro-beams to be displaced for inducing swing motion of the suspension secured to the rotor section and the magnetic head slider mounted thereon.