There is provided a radiation detection apparatus capable of effectively discriminating between noise and X-ray signal. The radiation detection apparatus includes a detector for detecting radiation and producing a detector output signal, a first differential filter having a time constant and operative to differentiate and convert the detector output signal into a first pulsed signal, a second differential filter having a time constant greater than that of the first differential filter and operative to differentiate and convert the detector output signal into a second pulsed signal, and a noise detection section for detecting noise based on the difference in timing between peaks of the first and second pulsed signals.