Method for producing a dust core, powder magnetic core and the coil component

A method of manufacturing a dust core using the soft magnetic material powder, the soft magnetic material powder and a first step of mixing a binder, a second compaction processing the resulting mixture through said first step of the step, and a third step of heat-treating the molded body obtained through the second step, the soft magnetic material powder is Fe, in Fe-Cr-Al alloy powder containing Cr and Al There, by the heat treatment, the surface of the soft magnetic material powder, than the interior of the alloy phase in a weight ratio Fe, the ratio of Al to the sum of Cr and Al to form a high oxide layer.