In the diffraction grating, the diffraction grating manufacturing method, the grating unit, and the X-ray imaging apparatus of the present invention, the grating region is formed on one main surface of the substrate, and the groove is formed on the other main surface facing the one main surface. Is.本発明の回折格子、この回折格子の製造方法、格子ユニットおよびX線撮像装置は、格子領域を基材の一方主面に形成し、前記一方主面に対向する他方主面に溝部を形成したものである。