PURPOSE: To prevent the generation of cracks on the molded material of the insulating resin to be used for the subject high-tension ignition coil by a method wherein a portion of the flexible primary coil bobbin is utilized as a cushioning material.

CONSTITUTION: The primary coil bobbin 2 formed by flexible resin is coupled into one unitary body. On the outer circumference of the bobbin 2, a molded body 8 consisting of insulating resin is formed enveloping the primary coil 3, the secondary coil bobbin 4, the secondary coil 5 and a portion of the high-tension coil 6. And, as the protruding sections 22 and 22 of the coil bobbin 2 are projected from both end section surfaces of the molded body, direct contact of the core 1 and the molded body 8 can be prevented. This method works as a cushioning material and the difference in the amount of expansion and contraction between the core 1 and the molded body 8 is absorbed by the flexibility of the bobbin 2, thereby enabling to prevent the generation of cracks on the molded body 8.