Abstract: A reactor coil 12 has a first coil element 121 formed by winding one flat type wire 17 edgewisely and rectangularly in a manner in which the wound flat type wire 17 is stacked rectangularly and cylindrically, and a second coil element 122 formed by winding the flat type wire 17 edgewisely and rectangularly at a winding terminating end point of the first coil element 121 in a direction opposite to the winding direction of the first coil element 121 and thereby stacked in a direction opposite to the stacking direction of the first coil element 121. Parts of the flat type wire 17 constituting each one edge of the first coil element 121 and the second coil element 122 are rendered to be projecting from outer circumferences of the first coil element 121 and the second coil element 122 by distances capable of obtaining insulation between a core and lead portions 121L, 122L formed in end portions of start-of-windings of the first coil element 121 and the second coil element 122.