An air bearing slider of a disk including a body having a surface facing a disk; a first rail base protruding from the surface facing the disk; a first rail portion protruding from the first rail base, the first rail portion including a cross rail separated from a leading end portion of the first rail base and extending perpendicular to a direction in which air enters, and a pair of side rails respectively extending from both ends of the cross rail parallel to the direction in which air enters; a negative pressure cavity defined by the first rail base; a second rail base protruding from the surface facing the disk; a second rail portion protruding from the second rail base; and an air flow channel disposed between the leading end portion of the first rail base and the cross rail, extending perpendicular to the direction in which air enters.