Abstract: To increase the spark energy being transferred from a spark plug to a fuel-air mixture, so that the maximum energy transfer occurs during the initial breakdown phase and electrode deterioration at the spark plug is prevented upon occurrence of subsequent arc conduction and glow phases, an inductive circuit is connected in parallel to the spark gap which is so dimensioned that the inductance has a time constant which inhibits substantial current flow through the shunt circuit upon breakdown of the spark gap, but permits flow of current during an arc and glow phase of the spark at the spark gap through the shunt circuit so that energy is drained from the spark gap during the plasma and glow phase.