X-ray detector

This X-ray detector which detects an X-ray and generates a corresponding output signal comprises: a TFT array including a plurality of pixel TFT circuits each generating the output signal according to the intensity of the detected X-ray; a gate circuit configured to apply, to the TFT array, a gate signal for driving the plurality of pixel TFT circuits; and a readout circuit configured to receive the output signal generated by each of the plurality of pixel TFT circuits and transmit the output signal to the outside. The gate circuit comprises: a gate chip-on film configured to generate the gate signal and apply the gate signal to the TFT array; and a gate connection FPCB circuitly connected to the gate chip-on film so as to receive a driving signal for generating the gate signal and transmit the driving signal to the gate chip-on film. The gate chip-on film and the gate connection FPCB are respectively arranged along different sides of the X-ray detector.