[Problem] To improve the sharpness and the contrast of small structures and the signal-to-noise ratio (S/N) of a planar member in a radio tomographic image generation device for generating a tomographic image by performing reconstruction using a successive approximation method. [Solution] A radio tomographic image generation device is provided with: a successive approximation reconstruction unit (41) for generating a plurality of reconstructed images having mutually different iterative calculation counts by means of a successive approximation method a region division unit (44) which uses a radiographic image signal to acquire information regarding structure, and uses this information regarding structure to divide a region where a tomographic image is generated, into a plurality of divided regions comprising information regarding mutually different structures and an image synthesis unit (45) which, based on the information regarding the structures of the divided regions, generates for each divided region a partial tomographic image using the reconstructed images having mutually different iterative calculation counts, and uses the generated partial tomographic images for each divided region to generate a tomographic image of a photographic subject.[Problème] Améliorer la définition et le contraste des petites structures et le rapport signal sur bruit (S/B) dun élément plan dans un dispositif de génération dimages radiotomographiques pour la génération dune image tomographique par reconstruction à laide dune méthode dapproximations successives. [Solution] La présente invention concerne un dispositif de génération dimages radiotomographiques qui contient : une unité de reconstruction par approximations successives (41) permettant de générer une multitude dimages reconstruites de comptes de calcul itératif mutuellement exclusifs par le biais dune méthode par approximations successives une unité de divisions par région (44) qui acquiert des informations sur la structure
