Perpendicular magnetic recording medium and a magnetic reproducing apparatus

A magnetic recording-reproducing apparatus, comprising:

• a magnetic recording disk;
• driving mechanism supporting and rotating said magnetic recording disk;
• and
• a magnetic head recording information in and reproducing the recorded information from said magnetic recording disk;
• wherein said magnetic recording disk comprises a nonmagnetic substrate, a cobalt alloy bias layer formed on said nonmagnetic substrate, a soft magnetic layer formed on said cobalt alloy bias layer and containing iron or cobalt, and a perpendicular magnetic recording layer, wherein the direction of residual magnetization of said cobalt alloy bias layer faces one direction of its radial direction, and said perpendicular magnetic recording medium satisfies the relationship given below:
• Mssoft×(tsoft−40 nm)>Mssoft×40 nm+Msbias×tbias
• where, tbias denotes the thickness of said cobalt alloy bias layer, Msbias denotes the saturation magnetization of the cobalt alloy bias layer, tsoft denotes the thickness of said soft magnetic layer, which falls within a range of between 40 nm and 200 nm, and Mssoft denotes the saturation magnetization of said soft magnetic layer.