1. A radiation image recording and read-out method for use in a radiation image recording and read-out system, in which a radiation image recording operation for recording a radiation image of an object, a radiation image read-out operation, and an erasing operation are performed iterately on an identical stimulable phosphor sheet, the method comprising the steps of: i) performing a residual image read-out operation on the stimulable phosphor sheet, which has been subjected to the erasing operation, a residual image signal, which represents a residual image remaining on the stimulable phosphor sheet after the stimulable phosphor sheet has been subjected to the erasing operation, being thereby acquired, ii) performing a radiation image recording operation for recording a radiation image of an object on the stimulable phosphor sheet, which has been subjected to the residual image read-out operation, iii) performing a radiation image read-out operation on the stimulable phosphor sheet, on which the radiation image of the object has been recorded, a radiation image signal, which represents the radiation image of the object, being thereby acquired, the thus acquired radiation image signal containing a residual image signal, which represents the residual image, and iv) subtracting the residual image signal, which represents the residual image, from the radiation image signal, which represents the radiation image of the object and which contains the residual image signal, whereby a radiation image signal, which represents the radiation image of the object and which is free from the residual image signal, is acquired.