A device including two plasma generation electrodes, a series resonator having a resonant frequency above 1 MHz and including a capacitor with two terminals, and an induction coil surrounded by a screen, the capacitor and the coil being placed in series, the electrodes being connected to the respective terminals of the capacitor. The ratio of the spark plug to the radius of the screen is equal to 0.56. The device can optimize the Q-factor of such a device by adjusting the radius of the coil to that of the screen.