A ferrite sintered body is composed of an oxide containing, as metal element, at least Fe and Zn and at least one selected from Ni, Cu and Mn. This sintered body contain Fe of 42 to 50 mol % in terms of Fe.sub.2O.sub.3, and Zn of 15 to 35 mol % in terms of ZnO. When the Zn concentration in the sintered body interior is taken to be 1, the Zn concentration in the surface vicinity is 0.8 to 12. This increases the surface resistance of the ferrite sintered body and lowers its core loss.