A magnetic head slider has a plurality of rail planes to generate a floating force by using an air flow passing through a region between a group of the rail planes and a magnetic disk rotated at a constant rotating speed, and the slider floats up into the air according to the floating force. Also, the slider has a first pad arranged near an air inflow end of one rail plane and a second pad arranged near an air outflow end of the same or another rail plane, and a height of the first pad and a height of the second pad respectively range from 20 to 50 nm. Therefore, a coefficient of a friction between the pads and the magnetic disk can be reduced, and the wear of the pads can be prevented. Also, the contact of an electro-magnetic transducing device attached to the air outflow end of the rail plane with the magnetic disk can be prevented.