A method for measuring a dose of irradiation with a beam of ionizing radiation capable of creating Cherenkov radiation, in which a scintillator for emitting scintillation light, whose intensity is a function of the dose of this beam irradiating this scintillator, is arranged below this beam, the scintillator is coupled, via an optical fiber, to a device for measuring the light emitted by the scintillator, and the quantity of light transmitted by the optical fiber is measured, is described. The light emerging from the opposite end of the optical fiber is filtered using two bandpass filters having cutoff bands in different parts of the spectrum, the intensity of the light coming from these two filters is measured a plurality of times, and the pluralities of quantities of scintillation light and Cherenkov radiation are calculated on the basis of these measurements to deduce a first irradiation dose value.