Provided is an X-ray imaging apparatus and a method of X-ray imaging, with which the apparatus can be reduced in size and a differential phase image or a phase image with consideration of an X-ray absorption effect of an object can be obtained.X-rays are spatially split, and a first attenuation element in which the transmission amount of X-rays continuously changes in accordance with the displacement when the X-rays pass through an object is used. Transmittance is calculated by using the first attenuation element and a second attenuation element that is different from the first attenuation element with respect to an amount of change or a characteristic of change in the transmission amount of X-rays in a direction of a displacement of the X-rays. A differential phase image and the like of the object are calculated using the transmittance.