IGNITER

PROBLEM TO BE SOLVED: To surely maintain and form a spark discharge by making an igniter automatically correspond to an insufficient state of the spark discharge so as to regulate an ignition energy. SOLUTION: A spark discharge detection means such as shunt resistor 12 or the like for detecting a spark discharge generating state at a secondary side of a transformer on the basis of consumption current of a drive circuit part 5 at a primary side of the transformer, a judgment means such as level judging circuit 14 for judging a spark discharge forming state on the basis of a detection result of the spark discharge generating state and an ignition energy regulation means such as drive circuit 15, transistor or the like for increasing excitation current at the primary side of the transformer by the drive circuit 5 so as to increase the ignition energy generated at the secondary side of the transformer are provided.