In an X-ray CT scanner having an X-ray tube which applies an X-ray spreading in a body axis direction of a subject, and an X-ray detector having a wide imaging range which detects the X-ray passed through the subject and converts the detected X-ray into an electric signal, a desired image creation time is set by use of a specific CT value curve in a console input unit before scanning with the X-ray. After the scanning, data of the CT value change curve is generated based on the obtained projection data. An image creation range in the generated change curve is determined based on an image creation range set in the console input unit, and the image creation is performed in the image creation unit based on the determined image creation time.
