An R-T-B—C rare earth sintered magnet (R═Ce, Pr, Nd, Tb, or Dy; T=Fe) is obtained by mixing an R-T-B—C magnet matrix alloy with an R fluoride and an R-rich R-T-B—C sintering aid alloy, followed by pulverization, compaction and sintering. The sintered structure consists of an R2T14B type crystal primary phase and a grain boundary phase. The grain boundary phase consists essentially of 40-98 vol % of R—O1-x—F1+2x and/or R—Fy, 1-50 vol % of R—O, R—O—C or R—C compound phase, 0.05-10 vol % of R-T phase, 0.05-20 vol % of B-rich phase or M-B2 phase (M=Ti, V, Cr, Zr, Nb, Mo, Hf, Ta or W), and the balance of an R-rich phase.