an ignition system for an internal combustion engine is widely known which includes a primary current control switch circuit adapted to be turned off at an ignition position to interrupt flowing of a primary current through an ignition coil , to thereby induce a high voltage for ignition across the ignition coil . continuation of the flow of the primary current causes an increase in power consumption and generation of heat from the ignition coil . an ignition system of the present invention utilizes charging and discharging of a control capacitor to permit control over the time for which the primary current is flowing to be accomplished with a simple structure . a discharge resistor which is arranged in parallel with the control capacitor carries out discharge of the control capacitor to interrupt the flow of the primary current when the internal combustion engine is stopped .