PURPOSE: To prevent crystal grains from becoming large and control a distribution of final grain diameters after a sintering process, by reducing a mean diameter and distribution of the grains in permanent magnet minute powder.

CONSTITUTION: A R-Fe-B group sintered permanent magnet, whose sintered crystal grains are all made to be essentially within the range of 3-30μm in their final grain diameters (n) by using minute powder obtained by moreover powdering minute powdered grains so as to have a uniform granular degree, is provided with excellent magnetic characteristics. The sintered permanent magnet, containing crystal grains of less than 3μm in their final grain diameters (n) after the sintering process, is remarkably deteriorated in the magnetic characteristics, caused by oxidation during the manufacturing process. On the other hand, a sintered permanent magnet, containing crystal grains in excess of 30μm in their final grain diameters (n) after the sintering process, is also deteriorated in their magnetic characteristics, caused by inferior orientation. Constituents of the sintered permanent magnet are permitted to be ones as known, without special limitation, and generally with R=5W20atom% and B=2W15atom%.