Common mode choke coil

A common mode choke coil, comprising:

• a first coil conductor provided on a first coil forming surface in an insulator and wound around a coil axis;
• a second coil conductor provided on a second coil forming surface in the insulator and wound around the coil axis;
• and
• a third coil conductor provided on a third coil forming surface in the insulator and wound around the coil axis,
• wherein the first coil conductor, the second coil conductor, and the third coil conductor extend parallel with each other in a first region in plan view as seen from an axial direction along the coil axis, and
• in the first region, a line segment of the first coil conductor in an n+1th turn, a line segment of the second coil conductor in the n+1th turn, and a line segment of the third coil conductor in the n+1th turn are plane-symmetrical to a line segment of the first coil conductor in an n-th turn, a line segment of the second coil conductor in the n-th turn, and a line segment of the third coil conductor in the n-th turn, respectively, with respect to a virtual plane extending through a midpoint between the line segment of the first coil conductor in the n-th turn and the line segment of the first coil conductor in the n+1th turn and extending parallel with the coil axis (where n is such a positive real number that n+1 exceeds none of a number of turns of the first coil conductor, a number of turns of the second coil conductor, and a number of turns of the third coil conductor).