A reactive sputtering method is provided for producing a magnetic layer in a stable manner with good reproducibility. One aspect of the invention is to form a magnetic layer for a magnetic recording medium without adversely affecting magnetic properties. Carbon oxide gas is added at the time of reactive sputtering. In one embodiment, a method for producing a magnetic recording medium includes forming at least a soft magnetic layer and a magnetic layer above a substrate, wherein forming said magnetic layer includes sputtering with argon gas and carbon oxide gas.