A slider support mechanism of a leaf-spring type movable only in a direction perpendicular to a surface of a disk and having a torsional rigidity equal to or more than 100 gfmm/rad and a spring constant within a range of 0.01-0.5 mg/.mu.m acts a load of 20-100 mg on a magnetic head slider to permit the slider to run in a liquid flying or contact condition. The load equal to or less than 100 mg is stably loaded on the magnetic head slider. Further, the magnetic head slider is not substantially rotated with respect to the magnetic disk surface. Accordingly, a slider running system of a liquid flying type or a solid contact type having a flying amount of 10-40 nm is made possible. Thus, the magnetic disk apparatus of high-density recording and high reliability is provided.