A magnetic core made of a mixed material including powder of an amorphous soft magnetic iron alloy and about 10% by volume or more of nonmagnetic inorganic powder, the amorphous soft magnetic iron alloy being expressed by the following composition: Fe100-a-b-x-y-z-w-tCOaNibMxPyCzBwSit wherein M is one or two or more elements selected from among Cr, Mo, W, V, Nb, Ta, Ti, Zr, Hf, Pt, Pd and Au, and a, b, x, y, z, w and t represent composition ratios satisfying 0 atom %≦x≦3 atom %, 2 atom %≦y≦15 atom %, 0 atom %≦z≦8 atom %, 1 atom %≦w≦12 atom %, 0.5 atom %≦t≦8 atom %, 0 atom %≦a≦20 atom %, 0 atom %≦b≦5 atom %, and 70 atom %≦(100-a-b-x-y-z-w-t)≦80 atom %.