A bending device for a wire includes a holder including a stepped part, the stepped part includes a side-surface corner and a flat surface, and the side-surface corner includes a curved surface. The bending device includes a guide member configured to push the wire against and along the curved surface, and the guide member revolves around a rotational axis of the guide member. The rotational axis of the guide member is disposed on a same axis as a center of the circle defining the curved surface of the holder.