a digital x - ray imaging apparatus comprises an x - ray generator 6 for generating x - rays toward a subject , an x - ray imaging device 7 for detecting an image of x - rays having passed through the subject , a swivel member 4 and a horizontal movement means 8 provided with the x - ray generator 6 and the x - ray imaging device 7 opposed to each other to relatively move the x - ray generator 6 and the x - ray imaging device 7 with respect to the subject , a cpu 21 for producing a tomographic image in accordance with an imaging signal from the x - ray imaging device 7 , frame memories and an image display unit 26 for displaying the tomographic image . the x - ray imaging device 7 includes a mos image sensor having a plurality of two - dimensional light - receiving pixels . with this configuration , a tomographic image along a given tomographic plane can be produced by a signal x - ray imaging operation , and the imaging sensitivity of the digital x - ray imaging apparatus can be enhanced .