Disclosed is an apparatus for rolling a substantially planar electric wire by more than one turn into a spiral shape. The apparatus includes an inner pressing member having an outer surface, an intermediate pressing member having radially inner and outer surfaces, and an outer pressing member having an inner surface. The inner and intermediate pressing members together press a first part of the electric wire between the outer surface of the inner pressing member and the inner surface of the intermediate pressing member, thereby plastically deforming the first part to extend along the outer surface of the inner pressing member. The intermediate and outer pressing members together press a second part of the electric wire between the outer surface of the intermediate pressing member and the inner surface of the outer pressing member, thereby plastically deforming the second part to extend along the outer surface of the intermediate pressing member.