Abstract: In a winding portion of a first wire and a winding portion of a second wire wound around a winding core portion in a state of being adjacent to each other, insulating coatings include large-diameter portions and small-diameter portions having an outer diameter smaller than an outer diameter of the large-diameter portions. The large-diameter portions and the small-diameter portions are distributed over a plurality of parts in a direction in which the wires extend. Spaces are formed between the first winding portion and the second winding portion due to a difference in size in a radial direction between the large-diameter portions and the small-diameter portions and contribute to a reduction of electrostatic capacity.

Abstract: An ignition plug includes: an insulator provided with a shaft hole formed therein; a metal fitting caulked to support the insulator from an outer periphery side thereof; and a talc material filled in an annular space provided between an outer peripheral surface of the insulator and an inner peripheral surface of the metal fitting. A first annular member and a second annular member are provided at an end portion of the annular space, the end portion being positioned in a center electrode side along the center axis in the annular space, the second annular member is in contact with the first annular member from an opposite side of the center electrode.

Abstract: An ignition plug includes: an insulator provided with a shaft hole formed therein; a metal fitting caulked to support the insulator from an outer periphery side thereof; and a talc material filled in an annular space provided between an outer peripheral surface of the insulator and an inner peripheral surface of the metal fitting. A first annular member and a second annular member are provided at an end portion of the annular space, the end portion being positioned in a center electrode side along the center axis in the annular space, the second annular member is in contact with the first annular member from an opposite side of the center electrode.