Abstract: [Object] To provide a high-performance rare earth-based magnet exhibiting a high coercive force or a high residual magnetic flux density even when the content of a rare earth element such as Dy or the like which is scarce is reduced. [Construction] A rare earth-iron-boron based magnet includes a crystal grain boundary layer enriched in element M (M is at least one rare earth element selected from Pr, Dy, Tb, and Ho) by diffusion of the element M from the surface of the magnet, wherein the relation between the coercive force Hcj and the content of the element M in the whole of the magnet is represented by the following expression: Hcj?1+0.2×M (wherein 0.05?M?10) wherein Hcj is the coercive force (unit: MA/m), and M is the content of the element M in the whole of the magnet (% by mass). Furthermore, the magnet satisfies the following expression: Br?1.68?0.17×Hcj wherein Br is the residual magnetic flux density (unit: T).

Abstract: A method of manufacturing a rare earth permanent magnet comprises the steps of: forming a rare earth magnet by applying mechanical processing to a magnet block material, thereby damaging the surface of the magnet and causing a magnetic characteristic (BH)max of the magnet to deteriorate, followed by transforming a rare earth metal or an alloy thereof into fine particles or a vapor, and allowing the fine particles or vapor to diffuse and permeate the magnet, thereby improving the quality of the damaged magnet surface portion so that the magnetic characteristic (BH)max is recovered.