An X-ray moving image radiographing apparatus includes an X-ray detector configured to detect an X-ray transmitting through a subject to acquire a subject image, an image processing unit configured to process an X-ray radiographic image output from the X-ray detector, and a control unit configured to capture a mask image by selectively scanning X-ray focal positions of an X-ray source which has a plurality of X-ray focal points so that an X-ray incident angle varies with respect to a target point of the subject, and to capture a moving image after a predetermined work is performed on the subject by selectively scanning X-ray focal positions of the X-ray source similar to the scanning operation used to capture the mask image.