A head supporting device with a loading/unloading mechanism and a disk drive unit using the head supporting device. The head supporting device and a voice coil motor (VCM) make up a head actuator of the drive system. The head actuator has i) a support arm rotatable on a bearing, moving in directions along the radius of a recording medium and vertical to the surface of the medium; ii) a magnetically levitating head on a slider facing the medium; and iii) resilient member for applying force to the arm in a direction close to the medium. The VCM has a pair of yokes, a magnet, and a coil. When the head is lead to a head retracting position, the other end of the arm is pulled by the interaction of a magnetic member and the magnet at the resting position and adjacencies. This eases the load on the VCM, contributing to a compact and slim disk drive unit with toughness and rapid data-access.