When the flying height of a magnetic head slider lowers, there arises the problem that the magnetic head slider assumes a forwardly falling attitude and a front edge portion of a leading end of the magnetic head slider comes into contact with a magnetic disk surface, causing damage to the disk surface. To address the problem, one aspect of the invention is directed to a magnetic head slider which includes an air bearing surface, a leading end and a trailing end. Three flying pads are formed on the air bearing surface and a step bearing surface is formed around the first and second flying pads near the leading end and a negative pressure groove for producing a negative pressure is formed in such a manner that the leading side is surrounded by the step bearing surface. The third flying pad is formed near the trailing end and is provided with a magnetic head. A step bearing is formed on the leading side of the third flying pad. Further, the magnetic head slider is formed with an aperture in a front edge portion of the leading end.