1. An X-ray diagnostic apparatus comprising: a designating section which designates a region of interest on not less than one image of a plurality of X-ray diagnostic images forming a moving image, when continuously displayed, on the basis of an input from an operator; a position estimating section which estimates corresponding areas on the remaining images of the plurality of images which correspond to the region of interest; and an image processing section which shifts the region of interest and the respective corresponding areas to appropriate positions on the respective images.