An outer conductor portion includes an outer conductor and a pair of outer terminals. The outer conductor is formed into a substantially cylindrical shape extending in the z-axis direction. The outer terminals are drawn toward the positive z-axis direction side of the outer conductor. In a plan view in the z-axis direction, the outer terminals are each bent in a direction outwardly from the outer conductor, and face each other across the outer conductor. An insulator has two sides, an upper surface in contact with a positive z-axis direction-side end portion of the outer conductor, and a lower surface in contact with the outer terminals at the sides, and thereby is nipped by the outer conductor portion in the z-axis direction. A central conductor is attached to the insulator, and is provided in a region surrounded by the outer conductor.