A TFT readout system radiation image detector capable of satisfactorily removing noise signals generated by the parasitic capacitors formed in the vicinity of the respective intersections between gate control signal lines and charge signal lines. The detector includes charge detecting elements for storing charges generated by receiving radiation; gate control signal lines through which a gate control signal flows to control the switching element of each charge detecting element; charge signal lines to which charge signals stored in the storage sections flow out; and delay circuits provided for the switching elements of respective charge detecting elements to delay the rise time of the gate control signal. Charge signals flowed out to the charge signal lines after the rise time are detected to differentiate the detection timings of the charge signals, and noise signals generated a when outputting of the gate control signal is initiated.