In the radiographic apparatus of this invention, when obtaining long images in a longitudinal direction, a correcting device corrects radiographic images based on overlapping areas of a plurality of radiographic images based on the radiation detected whenever a relative movement is made in the same direction, an image decomposing device decomposes corrected radiographic images for every predetermined distance, and an image composing device composes the decomposed images for each of the same projection angles to obtain a projection image for each projection angle. Thus, with a reconstruction processing device carrying out a reconstruction process based on the composed projection images, sectional images having a long field of view in the longitudinal direction can be obtained, while reducing luminance differences among different radiographic images.