PURPOSE: To heighten efficiency of diagnosing by making simultaneous image reading by an unprocessed X-ray film image and image reading of an image processed X-ray digital image.

CONSTITUTION: When an X-ray digital image for one image from an X-ray television unit is inputted to an element 2, it is displayed like a liquid crystal television, and a fluorescent lamp 4 provided on the back of the element 2 is lit up, and thereby, image observation, i.e. image reading is made possible at high dynamic range. When the element 2 is not in operation, the element 2 becomes nearly transparent. By attaching an X-ray film image photographed by an X-ray television unit, etc., by a clip 3 similarly with an X-ray digital image, and lighting up a fluorescent lamp 4, image reading is made possible at high dynamic range similar to an ordinary showcase unit. By displaying an X-ray digital image in the element 2, and attaching an X-ray film image by a clip 3, the two can be observed at the same time.