The present invention provides a Mn--Zn ferrite which is low in the loss in the frequency range between a few 10 kHz and a few 100 kHz and high in the saturation magnetic flux density in the vicinity of 100.degree. C. The present invention comprising the steps of compacting a powder having a specific surface area (based on the BET method) of 2.0 to 5.0 m.sup.2/g and a 50% particle size of 0.7 to 2.0 .mu.m into a compacted body having a predetermined shape and obtaining a sintered body by sintering the compacted body. It is preferable that a Mn--Zn ferrite comprises, as main constituents, 54 to 57 mol % of Fe.sub.2O.sub.3, 5 to 10 mol % of ZnO, 4 mol % or less (not inclusive of 0%) of NiO, and the balance substantially being MnO.