Method for manufacturing R-T-B based sintered magnet

Disclosed is a method for manufacturing an R-T-B based sintered magnet, said method comprising: a step for preparing a plurality of starting materials of the R-T-B based sintered magnet (wherein R is at least one member of rare earth elements and essentially comprises Nd and/or Pr, and T is at least one member of transition metal elements and essentially comprises Fe); a step for preparing a plurality of alloy powder grains that contain 20-80 mass% inclusive of a heavy rare earth element RH (wherein the heavy rare earth element RH comprises Tb and/or Dy) and have a grain size of not more than 90 [mu]m; a step for loading into a treatment container the aforesaid starting materials of the R-T-B based sintered magnet and 2-15 wt% inclusive, relative to the starting materials of the R-T-B based sintered magnet, of the aforesaid alloy powder grains; and a step for supplying and diffusing RH by heating and simultaneously rotating and/or oscillating the treatment container to thereby continuously or intermittently m