1. An X-ray diagnosis apparatus comprising: an image generating unit that generates X-ray images; a feature point detecting unit that detects a position of a feature point on a first frame of an X-ray image generated by the image generating unit; a correction-image generating unit that generates a first correction image from a second frame of the X-ray image through at least one of image shift and image transformation, by substantially matching the corresponding position of the feature point detected on the second frame of the X-ray image by the feature point detecting unit, with the position that is a position of the feature point already detected by the feature point detecting unit in the first frame of the X-ray image; the correction-image generating unit generating a second correction image from a third frame of the X-ray image through at least one image shift and image transformation, by substantially matching the corresponding position of the feature point in the third frame of the X-ray image by the feature point detecting unit, with the position of the feature point already corrected in the first correction image; and a display control unit that performs control of displaying the generated correction image as an image for display so as to be sequentially displayed as a moving image onto a display unit, each time when the correction-image generating unit newly generates the correction image.