A dust core is prepared from an iron powder with a particle size of 75-200 .mu.m having added thereto 0.015-0.15 wt % of silica sol, 0.05-0.5 wt % of a silicone resin, and 10-50 wt % based on the silicone resin of an organic titanium compound. By subjecting the iron powder to a curing treatment at 50.degree.-250.degree. C., compacting the powder, and annealing in an inert atmosphere at 550.degree.-650.degree. C., there is obtained a dust core consisting essentially of iron powder particles with a particle size of 75-200 .mu.m, 0.03-0.1% by weight of Si, 15-210 ppm of Ti, and 300-2,500 ppm of oxygen.