A drum core includes a core portion that extends in an axial direction, first and second flange portions respectively disposed at first and second ends of the core portion in the axial direction, and first and second terminal electrodes respectively disposed at the first and second flange portions. The first flange portion includes a bottom surface that is substantially parallel to the axial direction and on which the first terminal electrode is disposed, an outer end surface that is substantially perpendicular to the axial direction and that faces outward away from the core portion, and a first ridge portion and a second ridge portion respectively disposed at a first end and a second end of the outer end surface in a width direction substantially parallel to the bottom surface and the outer end surface, and the first ridge portion and the second ridge portion have different shapes.