A HGA of the invention includes a slider; a micro-actuator to adjust the position of the slider; and a suspension to load the slider and the micro-actuator. The micro-actuator includes two side arms; a load plate for supporting the slider, which is connected with at least one of the side arms; a piezoelectric element connected with the side arms; and a base shaft to couple with the suspension, which is connected with the side arms and positioned between the load plate and the piezoelectric element. The invention also discloses a disk drive unit using such a HGA.