The X-ray imaging device (100) is provided with an X-ray source (1), a plurality of gratings, a moving mechanism (8), and an image processing unit (6). The image processing unit (6) is configured to generate a phase-contrast image (16) by associating a pixel value in each pixel of a subject (T) in a plurality of subject images (10) with phase values of a Moire fringe (30) at each pixel and aligning the pixel of the subject of the same position in the plurality of subject images.