PURPOSE: To increase the sintering density of a sintered magnet alloy of Ni-Al- Fe or Ni-Al-Co-Fe and to enhance the magnetic characteristics by adding a specified amount of S to the composition of the alloy of further adding B or P.

CONSTITUTION: In the manufacture of a sintered magnet alloy of Ni-Al-Fe or Ni-Al-Co-Fe, powdered starting materials for the alloy are mixed with a powdered Fe-S mother alloy so as to make the S content 0.01W1.0%, or they are further mixed with a powdered Fe-B alloy mother and/or a powdered Fe-P mother alloy so as to make the B content 0.01W0.5% and the P content 0.01W 3.0%. The mixture is press-molded under high pressure and sintered at 1,300°C for 3hr. The sintered body is rapidly cooled from such a high temp. in a magnetic field and aged to increase the sintering density to that close to the theoretical density. Thus, the magnetic characteristics such as residual magnetic flux density are enhanced.