An antenna core produced by shaping a soft magnetic
metal powder with the use of a resin as a binder, wherein the soft magnetic
metal powder is an amorphous soft magnetic
metal powder or a
nanocrystal-containing amorphous soft magnetic
metal powder, of the general formula (1): (Fe1-x-yCoxNiy)100-a-b-cSiaBbMc (1), and wherein the resin as a binder is a thermosetting resin. In the formula, M is at least one element selected from the group consisting of Nb, Mo, Zr, W, Ta, Hf, Ti, V, Cr, Mn, Y, Pd, Ru, Ga, Ge, C, P, Al, Cu, Au, Ag, Sn and Sb. Each of x and y is an
atomic ratio and each of a, b and c an atomic %, satisfying the relationships: 0≦x≦1.0, 0≦y≦0.5, 0≦x+y≦1.0, 0≦a≦24, 1≦b≦30, 0≦c≦30 and 2≦a+b≦30.