A method and device for determining ionizing radiation. The method for determining ionizing radiation comprises the steps of applying a constant voltage across an organic semiconducting material sensor prior to and after exposure of the sensor to the ionizing radiation; measuring and converting the current passing through the sensor proportional to the conductivity or resistivity of the sensor which in turn is proportional to the ionizing radiation in the sensor, into a proportional analog voltage value; and if desired converting the analog voltage value into digital value; and comparing the analog / digital values obtained prior to and after exposure of the sensor to the ionizing radiation and computing the ionizing radiation based on the change in the analog / digital values. The electronic device for determining ionizing radiation comprises an organic semiconductor resistor (2) connected to a constant voltage source (3) and to a current to voltage converter (4), an analog to digital converter (5) connected to the current to voltage converter and a microprocessor (6) connected to the analog to digital converter.