Abstract: An ignition system of the type incorporating, instead of the usual distributor, high-voltage rectifier diodes connected between the secondary winding of an ignition coil and respective spark plugs. In response to voltages developed in the secondary winding in its opposite directions the diodes function to cause discharges at the spark plugs in the firing order of the engine. Each diode is composed of a multiplicity of laminated silicon rectifier diode chips each having a reverse breakdown voltage in the range of 400-850 volts. The reverse breakdown voltage of each diode is 1.1 to 1.8 times the maximum discharge voltage of the spark plugs. Thus constructed, the diodes can well withstand overvoltages that may develop in the secondary circuit of the ignition system.