If a large external impact is applied to a magnetic disc apparatus, a slider jumps from a disc surface and rotates. When the slider jumps and rotates, its edges re-contact the disc surface to damage this surface. To reduce the rotation angle of the slider to control its position if an impact is effected, the present invention provides a roof on a load arm to reduce the contact angle at which the slider contacts the disc surface in order to relax the impact upon a contact.