A radiographic image detection device subtracts a first offset image from a radiographic image to generate a primary corrected image, subtracts a second offset image from an immediately preceding offset image to generate an offset difference image, performs gain correction on the primary corrected image on the basis of a first gain image to generate a secondary corrected image, performs gain correction on the offset difference image on the basis of a second gain image to generate a gain-corrected offset difference image, performs a low-pass filtering process on the gain-corrected offset difference image, and subtracts the gain-corrected offset difference image subjected to the low-pass filtering process from the secondary corrected image to generate a tertiary corrected image.