PURPOSE: To make it possible to employ one piece as two pair of ignition coils, and make an ignition system small-sized, by winding two pairs of coils around a magnetic pole core formed in the rectangular direction, in the manner in which the mutual flux does not interfare with each other.

CONSTITUTION: Around a magnetic pole core in a cross-shaped form in the rectangular direction, two pairs of primary coils 2 and secondary coils 3 are wound in the manner in which they intersect at right angles and have no mutual interaction of magnetic flux. Then it becomes possible to employ one piece as two pair of ignition coils. The ignition system is made small-sized, therby.