According to a radiation imaging device of the invention, a revising data obtaining portion 33 computes an offset value of a temperature lower than actual temperature based on an offset value obtained by an offset value obtaining portion 29 and a linear approximating curve computed by a linear approximating curve computing portion 31. The offset value of a temperature lower than actual temperature means a value lower than an actual offset value, and thus output data for a detecting element A does not excessively undergo offset revise. Moreover, an image after an offset revise undergoes a re-revise for modifying image deterioration, thereby undergoing image processing such as contrast enhancement. The result is that a lack of image information due to excessive offset revise can be avoided and a high quality radiation transmitted image can be formed.
