A magnetic head supporting mechanism includes a head positioning actuator having an arm, and a load beam connected to the arm. The load beam has a gimbal. The gimbal includes a magnetic head slider fixing portion on which a magnetic head slider having a magnetic head is mounted, a first pair of beams extending from opposite sides of the magnetic head slider fixing portion along a traverse direction of the load beam perpendicular to a longitudinal direction thereof, and a second pair of beams respectively connected to the first pair of beams and extending so as to face the opposite sides of the magnetic head slider fixing portion.