A measuring device including: a supply circuit for radiofrequency ignition including a transformer including a secondary winding connected to at least one resonator having a resonance frequency higher than 1 MHz, and including two electrodes capable of generating a spark upon an ignition control; a measuring capacitor connected in series between the secondary winding and the resonator; a measuring circuit of ionization current of the combustion gases in a cylinder of the internal combustion engine associated with the resonator, the circuit being connected at terminals of the measuring capacitor; and/or a measuring circuit that measures a voltage at the resonator terminals upon an ignition control, the circuit being connected to terminals of the measuring capacitor.