A magnetic head slider, for sliding on a magnetic disk, which has a leading edge, a trailing edge, an air bearing surface having a front step bearing of submicron depth made from the leading edge, and a rail surface made from the front step bearing. A negative pressure recess which is deeper than the front step bearing, is formed as a recess from the rail surf ace, and a side step bearing with a depth identical to that of the front step bearing is made from the rail surface. Side padB are provided which each have a width W and length L, wherein W is greater than L.