A radiation detector noise reduction method includes the step of detecting incident radiation with a radiation detecting section, the radiation detecting section having a plurality of pixels arrayed in the form of a matrix, reading out the detection signal from the radiation detecting section through a readouting section, and correcting the readout detection signal with a correction section, wherein the correction step includes the first sub-step of correcting the detection signal on the basis of a first correction value corresponding to noise originating in the radiation detecting section, and the second sub-step of correcting the detection signal on the basis of a second correction value corresponding to noise originating in the readouting section, the second sub-step being executed before the first sub-step.
