The spatial homogeneity of electrical characteristics in SiO2Si structures irradiated with fast electrons with a dose up to 1015 cm−2 is studied with a scanning mercury probe technique. It is shown that irradiation does not disturb the homogeneity of oxide film and interface, and in cases of structures having nonuniformly doped substrates it does not change the shape and the value of these inhomogeneities. At irradiation of the samples with charge distribution in oxide film fluctuating across the area, the amplitude of these fluctuations decreases proportionally to the growth in the mean value of the charge, the dependence on the irradiation dose being exponential.