A radiation detecting system is provided which comprises a radiation detecting apparatus comprising a pixel portion having a plurality of pixels arranged. Each pixel comprises a photoelectric conversion element and a switch element connected to the photoelectric conversion element, a drive circuit for operating the switch element to drive the photoelectric conversion element, and a wavelength converter for converting a radiation emitted from a radiation source into a light which can be detected by the photoelectric conversion element, a power source for applying a voltage to the photoelectric conversion element, and a controller for controlling the radiation detecting apparatus and the power source, wherein the controlling unit controls the drive circuit to operate the radiation detecting apparatus to perform an initialization operation such that, after a start of applying the voltage to the photoelectric conversion element, during a period of stabilizing a dark current generated in the photoelectric conversion element at the time of applying the voltage, the pixel portion is initialized, to perform a reading operation for reading a radiation image information from the radiation detecting apparatus after an irradiation with the radiation, and to repeat the initialization operation at plural times.
