A manufacturing method of a sintered magnet, the method comprising: a) forming a pre-sintering body from a first magnetic powder and a second magnetic powder so that at least part of the second magnetic powder is provided at at least one inner portion of the pre-sintering body and surrounded from at least two opposite sides by the first magnetic powder, wherein the first magnetic powder has an R-T-B structure, wherein R is at least one selected from the group consisting of Y, Ce, La, Pr, Nd, Sm, Eu and Gd, and T is one or more transition metal elements including Fe, wherein the second magnetic powder contains at least one heavy rare earth element, wherein a melting temperature T M1 of the first magnetic powder is higher than a melting temperature T M2 of the second magnetic powder, the pre-sintering body having a thickness of at least 6 mm, b) sintering the pre-sintering body at a temperature T S being higher than the melting temperature T M2 of the second magnetic powder and lower than the melting temperature T M1 of the first magnetic powder, thereby creating a main phase of grains from the first magnetic powder with a grain boundary phase in-between the grains, and an HRE reservoir from the second magnetic powder, c) annealing the sintered pre-sintering body at an annealing temperature T A lower than the sintering temperature T S, thereby causing inter-grain diffusion of HRE from the HRE reservoir zone to the grain boundary phase so that after the annealing the grain boundary phase contains at least one heavy rare earth element in a higher concentration than the main phase, characterised in that the sintering is Spark Plasma Sintering. a) forming a pre-sintering body from a first magnetic powder and a second magnetic powder so that at least part of the second magnetic powder is provided at at least one inner portion of the pre-sintering body and surrounded from at least two opposite sides by the first magnetic powder, wherein the first magnetic powder has an R-T-B structure, wherein R is at least one selected from the group consisting of Y, Ce, La, Pr, Nd, Sm, Eu and Gd, and T is one or more transition metal elements including Fe, wherein the second magnetic powder contains at least one heavy rare earth element, wherein a melting temperature T M1 of the first magnetic powder is higher than a melting temperature T M2 of the second magnetic powder, the pre-sintering body having a thickness of at least 6 mm, b) sintering the pre-sintering body at a temperature T S being higher than the melting temperature T M2 of the second magnetic powder and lower than the melting temperature T M1 of the first magnetic powder, thereby creating a main phase of grains from the first magnetic powder with a grain boundary phase in-between the grains, and an HRE reservoir from the second magnetic powder, c) annealing the sintered pre-sintering body at an annealing temperature T A lower than the sintering temperature T S, thereby causing inter-grain diffusion of HRE from the HRE reservoir zone to the grain boundary phase so that after the annealing the grain boundary phase contains at least one heavy rare earth element in a higher concentration than the main phase,