(a) forming a lower core layer;

(b) forming a first insulating layer around the lower core layer;

(c) simultaneously forming by plating a coil layer on the lower core layer with a coil insulating underlayer interposed therebetween and a first coil lead layer connected to the coil layer on the first insulating layer;

(d) forming a coil insulating layer of an inorganic material on the coil layer and the first coil lead layer;

(e) forming two openings in the coil insulating layer on the first coil lead layer to expose the first coil lead layer so that the two openings form a plating-forming opening and a current-carrying opening;

(f) simultaneously forming a first plating underlayer by plating a second plating underlayer on the first coil lead layer exposed through the plating-forming opening, and a current-carrying lead layer that is continuously provided from the surface of the first coil lead layer exposed through the current-carrying opening to a surface of the coil insulating layer, using the same material;

(g) simultaneously forming, by plating from the same material as the first plating underlayer, an upper core layer on the first plating underlayer and a base portion on the second plating underlayer in the plating-forming opening formed in the coil insulating layer by supplying a current from the current-carrying lead layer to the second plating underlayer in the plating-forming opening through the first coil lead layer facing the current-carrying opening, and further forming a first upper portion from the same material as that for the upper core layer by plating to extend from the base portion to an outside of the plating-forming opening using free plating growth from the base portion;

(h) forming a second upper portion, which is provided on the first upper portion and extends therefrom to the outside of the plating-forming opening and which has an outer shape having a height larger than that of the plating-forming opening, a width extending from the plating-forming opening to the surface of the coil insulating layer, and a convex-curved side surface, using free plating growth from the first upper portion by supplying a current to the first upper portion from the current-carrying lead layer through the first coil lead layer facing the current-carrying opening and the second plating underlayer in the plating-forming opening, so that a protrusion is formed from the base portion, the first upper portion, and the second upper portion;

(i) removing the current-carrying lead layer by ion milling; and

(j) forming a protective layer of an inorganic material on the second upper portion of the protrusion and the coil insulating layer.