To provide a correction method for an electric signal, in which the influence of an afterimage of previous image is reduced to the minimum in a radiation detecting panel and to provide a removal method for the afterimage.

This correction method for electric signal which is formed when a radiation detecting element comprising a photoconductive layer is exposed to a radiation and which displays an image comprising a plurality of pixels has (A) a step wherein the radiation detecting element is operated in such a way that the photoconductive layer is not exposed to the radiation and before-exposure electronic signal is read out in every pixel from the plurality of pixels, (B) a step wherein the photoconductive layer is exposed to the radiation, the radiation detecting element is operated and an exposure electronic signal is read out in every pixel from the plurality of pixels, and (C) a step wherein the before-exposure electronic signal is subtracted from the exposure electronic signal in every pixel.