An air bearing slider of a disk drive for moving a read/write head to a
desired position on a disk by being lifted above a surface of the disk
includes a body having a surface facing the disk. A first rail base
protrudes from the surface of the body facing the disk and has a U shape
open to a trailing end portion of the body. A first positive pressure
generating rail portion protrudes from the first rail base and includes a
cross rail separated from a leading end portion of the first rail base
and extending in a first direction perpendicular to a direction in which
air enters and a pair of side rails extending from both ends portion of
the cross rail in a second direction parallel to the direction in which
air enters. A negative pressure cavity is defined by the first rail base.
A second rail base protrudes from the surface of the body facing the disk
adjacent to the trailing end portion of the body. A second positive
pressure generating rail portion protrudes from the second rail base. A
negative pressure-generating pocket is formed in each of the side rails
and separate from the negative pressure cavity and open to the outside of
the side rails.