The method comprising the steps of: preparing a sintered body having (Rl) _x (Rh) a composition of _y T _z B _{s t} M; Preparing a precursor by carrying out the hot deformation processing on the sintered body; And at a temperature of 450 ℃ ~ 700 ℃ and a step of producing a rare-earth magnet by carrying out aging treatment on the precursor. In the method, the main phase is formed by a phase (RlRh) ₂ T ₁₄ B. On the grain boundary (RlRh) is _1.1 T ₄ B ₄ content was 0% by mass is more than 50% by mass or less. Rl represents a light rare earth element. Rh represents a rare earth element of. T is a transition indicates a metal. M represents at least one of Ga, Al, Cu and Co. x, y, z, s and t represents the mass% of the R1, Rh, T, B, and M. x, y, z, s and t have the following formula: represents a 27≤x≤44, 0≤y≤10, z = 100-xyst, 0.75≤s≤3.4, 0≤t≤3.