An Sm—Fe—N-based magnetic material according to the present disclosure includes a main phase having a predetermined crystal structure. The main phase has a composition represented by (Sm(1-x-y-z)LaxCeyR1z)2(Fe(1-p-q-s)CopNiqMs)17Nh (where, R1 is predetermined rare earth elements and the like, M is predetermined elements and the like, and 0.04≤x+y≤0.50, 0≤z≤0.10, 0≤p+q≤0.10, 0≤s≤0.10, and 2.9≤h≤3.1 are satisfied). A crystal volume of the main phase is 0.833 nm3 to 0.840 nm3. A manufacturing method of the Sm—Fe—N-based magnetic material according to the present disclosure includes nitriding a magnetic material precursor including a crystal phase having a composition represented by (Sm(1-x-y-z)LaxCeyR1z)2(Fe(1-p-q-s)CopNiqMs)17.