In the magnetic head slider locking apparatus according to the present invention, a spring portion takes a sandwiching posture in which a center region of a proximal-side engage portion sandwiches a magnetic head slider in a suspension longitudinal direction in cooperation with a distal-side engage portion when an operational force to the spring portion is released after the magnetic head slider has been mounted in a state where the spring portion has been elastically deformed from an initial posture to an elastically deformed posture. Paired arm are elastically deformed by paired side regions of the proximal-side engage portion that are moved upon posture change of the spring portion from the initial posture to the elastically deformed posture so as to take a distant posture in which a distance between the paired arm portions is wider than the width of the magnetic head slider, and are shifted to take a sandwiching posture of sandwiching the magnetic head slider from both sides in the suspension width direction upon posture change of the spring portion from the elastically deformed posture to the sandwiching posture.