The temperature properties of the initial permeability of a Ni--Cu--Zn based ferrite material are improved while the degradation of the magnetic properties of the ferrite material is being suppressed. The ferrite material is formed of a sintered body comprising, as main constituents, Fe.sub.2O.sub.3: 47.0 to 50.0 mol %, CuO: 0 to 7 mol %, NiO: 13 to 26 mol %, and ZnO substantially constituting the balance, wherein the sintered body comprises 40 ppm or less of P in terms of P.sub.2O.sub.5 and 50 to 1800 ppm of one or more additives of Al.sub.2O.sub.3, CaO and MgO in relation to the sum of the contents of the main constituents. In the Ni--Cu--Zn based ferrite material, the mean grain size can be set at 12 .mu.m or less and the standard deviation of the grain size can be set at 4.5 .mu.m or less.