A glass-ceramic-ferrite composition contains glass, a ceramic filler, and Ni—Zn—Cu ferrite. The glass contains about 0.5% by weight or more of R2O, where R is at least one selected from the group consisting of Li, Na, and K; about 5.0% by weight or less of Al2O3; about 10.0% by weight or more of B2O3; and about 85.0% by weight or less of SiO2 on the basis of the weight of the glass. The Ni—Zn—Cu ferrite accounts for about 58% to 64% by weight of the glass-ceramic-ferrite composition. The ceramic filler contains quartz and, in some cases, forsterite. The quartz accounts for about 4% to 13% by weight of the glass-ceramic-ferrite composition. The forsterite accounts for about 6% by weight or less of the glass-ceramic-ferrite composition.