IGNITION DEVICE FOR INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To provide an ignition device of an internal combustion engine capable of keeping a discharge voltage generated on a secondary winding substantially constant for a prescribed time without using a high withstand voltage element.SOLUTION: In an ignition device of an internal combustion engine including an ignition coil 10 generating high voltage on a secondary winding by increasing or decreasing electric current of a primary winding, a DC power source connected to the primary winding, an ignition plug 12 igniting a fuel by receiving high voltage generated in the secondary winding, and an IGBT 11 functioning as a switch for interrupting and conducting electric current of the primary winding, a capacitor 22 of a prescribed capacity is connected between a gate terminal and a collector terminal of the IGBT 11, and electric charge corresponding to the prescribed capacity, is supplied to the gate terminal from the capacitor 22 when the IGBT 11 is switched off to keep high voltage generated in the secondary winding at a specific value for a prescribed time in switching the IGBT 11 off.