A head gimbal assembly (HGA) including a slider, a micro-actuator and a suspension to load the slider and the micro-actuator. The micro-actuator includes a support base and a piezoelectric unit used for both position displacement adjustment and flying height adjustment. The support base includes a base, a moving plate, and a leading beam to connect with the base and the moving plate. The invention also discloses a method of manufacturing such micro-actuator and HGA, and a structure of a disk drive having the micro-actuator and HGA.