An object of the present invention is to provide an R-T-B based permanent magnet having a low coercive force and a low magnetizing field, and having a high residual magnetic flux density and a high minor curve flatness even in the low magnetizing field. Provided is an R-T-B based permanent magnet including a main phase including a compound having an R2T14B type tetragonal structure and a grain boundary phase existing between the main phases, in which R is at least one rare earth element including scandium and yttrium, T is at least one transition metal element including iron, or at least two transition metal elements including iron and cobalt, the grain boundary includes an R-T-B—C based compound having a higher R concentration, B concentration and C concentration than that of the main phase and having a lower T concentration than that of the main phase.