An ignition system providing power and duration controlled ignition spark, comprises a spark controller, first switching energy accumulator, storage capacitor, and second switching energy accumulator with an ignition coil. The ignition system utilizes dual means of switching energy accumulation, internal energy transfer, and three means of energy release to the ignition spark, working in all possible combinations managed by means of the spark controller depending on engine operating conditions, and provides continuous bipolar ignition spark. Spark profile is regulated by means of control signals (2) and (3) based on their frequency, duty cycle, interrelation, and running time.