An apparatus for supporting and reciprocating a magnetic head slider above a rotating magnetic disk comprises a carrying arm having a free end, a flexible base connected at one end thereof to the free end of the supporting arm, a pair of flexible fingers extending from the other end of the flexible base parallel to an axis of the carrying arm and defining therebetween a space, a traverse bar connecting two free ends of the fingers, and a flexible tongued member on which the magnetic head slider to be mounted, one end of the tongued member being connected to the traverse bar and the other end thereof extending into the space with gaps between the tongued member and the fingers and the base. A reduced part of a minimum cross-section is provided in each of the fingers. The reduced part is located between the one end of the tongued member and a center between the one end of the tongued member and the other end of the base.