An arrangement for the ignition of ignitable mixtures, especially a spark plug for producing sparks in otto-engines, which is constructed according to high-frequency standpoints and in which at least one condenser arranged in the spark plug is adapted to be charged to a high voltage and is adapted to be discharged as much as possible exclusively in the breakdown phase of the starting phase of the ignition spark by way of a booster gap also arranged in the spark plug and a main gap formed by an ignition electrode with respect to a ground electrode, whereby the breakdown voltage of the booster is higher than the breakdown voltage at the main gap. In particular, for achieving a compact constructive form, satisfactory from a manufacturing point of view, and for optimizing the ignition and flame development, the condenser and the main gap are connected in a series circuit in a preferred embodiment of the invention, with respect to which the booster gap is connected in parallel.