An R--Fe--B base sintered magnet having a composition of 12 17 at % of R (wherein R stands for at least two of yttrium and rare earth elements and essentially contains Nd and Pr), 0.1 3 at % of Si, 5 5.9 at % of B, 0 10 at % of Co, and the balance of Fe, containing a R.sub.2(Fe,(Co),Si).sub.14B intermetallic compound primary phase and at least 1% by volume of an R--Fe(Co)--Si grain boundary phase, and being free of a B-rich phase exhibits a coercive force of at least 10 kOe despite a reduced content of heavy rare earth.