Controlling the frequency of excitation of a radiofrequency spark plug.

The invention relates to a radiofrequency plasma generating device, comprising: a control module (30) generating a control signal (V1) to a control frequency, -a supply circuit (20) comprising a switch (M ) controlled by the control signal, the switch applying an excitation signal (V2) at an output of the supply circuit at the frequency defined by the control signal, -a resonator (10) having a resonant frequency greater at 1 MHz, connected to the output of the supply circuit and adapted to generate a voltage (U (t)) for the manufacture of a spark when energized by the excitation signal, said apparatus being characterized in that it comprises means (40, 50) for controlling the control module (30) adapted to modify the frequency of the excitation signal synchronously with the resonator control signal during the application of said signal excitation.