The present invention provides a method for producing an R-T-B-M sintered magnet having an oxygen content of less than 0.07 wt. % from R-T-B-M raw materials. The composition of R-T-B-M includes R being at least one element selected from a rare earth metal including Sc and Y. The composition also includes T being at least one element selected from Fe and Co. B in the composition is defined as Boron. The composition further includes M being at least one element selected from Ti, Ni, Nb, Al, V, Mn, Sn, Ca, Mg, Pb, Sb, Zn, Si, Zr, Cr, Cu, Ga, Mo, W, and Ta. The present invention provides for a step of creating an inert gas environment in the steps of casting, milling, mixing, molding, heating, and aging to prevent the powder from reacting with the oxygen in anyone of the above mentioned steps.