A bead core formation apparatus includes a rubber coating device that coats a circumferential surface of a steel wire with rubber, and two cooling rollers around which the rubber-coated wire, which is a steel wire coated with rubber, is wound. The second roller includes a first groove and a second groove around which the rubber-coated wire located at a downstream side of the first groove is wound. The diameter LB of a portion including the second groove is smaller than the diameter LC of a portion including the first groove.