A radiation image capturing apparatus includes an overlapping area specifying unit which acquires a plurality of radiation images of the plurality of image capturing ranges of an elongate test subject in advance, specifies overlapping areas in the radiation images, and registers information of the specified overlapping areas in an information table, an image joining unit which acquires a plurality of radiation images of the plurality of image capturing ranges of the elongate subject, and joins the acquired plurality of radiation images based on the information of the overlapping areas registered in the information table to generate a single joined radiation image, and an image generating unit for generating a tomographic image on an arbitrary image plane based on the joined radiation image.
