[en] A method to measure ionizing radiation dose based on the effect of electret discharge under ionizing radiation effect and on the measurement of residual charge, is suggested. To simplify the process of measurement electret state is created in a sensitive element, produced of a material with a wide forbidden zone, deep capture levels and high mobility of charge carriers. To create the electret state the sensitive element is placed into constant electric field and illuminated, to generate charge carriers. To measure the residual charge after irradiation of the sensitive element by the studied ionizing radiation it is illuminated by probing light with the intensity 10-1000 times lower than that for electret state creation, and the current change in the external circuit is measured. Diamond for which forbidden zone width constitutes 5.5 eV, depth of capture centres is 0.6-1.4 eV, electron mobility is 1800 cm²V^-1s^-1, hole mobility is 1200 cm²V^-1s^-1 can be used as a material for the sensitive element. The described method can be used to measure ionizing radiation dose in medicine and also for irradiation control when performing operations connected with X-rays and radiactive substances