Abstract: Spark gap measuring and monitoring method and device, for providing, during operation, a signal indicative of the intended performance of the spark gap (1), in particular a spark plug of a combustion engine. The device includes an electrical detecting element which is coupled inductively to a connecting lead (4) of the spark gap (1), for example a toroidal coil (8), which detecting element is connected to a processing circuit (9-11) for the purpose of converting the electrical signal produced by the detecting element into a measuring signal indicative of the spark gap (1) performance, for example the spacing (d) between the electrodes (2, 3). Measurement results obtained from an initial measurement can be established as reference data by means of memory elements and circuit elements. The measuring signal is then analyzed by means of an analyzing circuit (14) as a function of the reference data.