A head slider having a thin film magnetic head is mounted on a suspension assembly. The suspension assembly is comprised of a metal plate-like member, and a piezoelectric actuator for displacing the head slider relative to the suspension assembly. The piezoelectric actuator has a piezoelectric film, and a pair of electrode films placed so as to sandwich the piezoelectric film in between. The piezoelectric film and the pair of electrode films are formed in an order of one electrode film, the piezoelectric film, and the other electrode film on the plate-like member.