[Problem to be solved] A radiographic phase-contrast imaging apparatus includes two gratings including the first grating and the second grating, which are positioned parallel to each other at a predetermined interval, and obtains a radiographic phase-contrast image using these gratings, wherein a plurality of fringe images used to obtain a radiographic phase-contrast image are obtained by a single imaging operation.[Solution] The first and second gratings are adapted to form a moire pattern when a periodic pattern image formed by the first grating is superimposed on the second grating. Based on an image signal of the moire pattern detected by the radiographic image detector, image signals of the fringe images, which correspond to different pixel groups located at different positions from one another with respect to a predetermined direction, are obtained by obtaining image signals read out from pixels of each pixel group, which includes pixels arranged at intervals of a predetermined number of pixels in the predetermined direction, as the image signal of each fringe image, where the predetermined direction is a direction parallel to or a direction intersecting a period direction of the moire pattern other than a direction orthogonal to the period direction of the moire pattern. Then, a phase-contrast image is generated based on the obtained image signals of the fringe images.
