1. An X-ray device comprising: a camera configured to image an object and output the image of the object; a display member configured to display the image of the object and an image of an X-ray irradiation region of the object; an X-ray irradiation region controller configured to control the X-ray irradiation region of the object to which X-rays are irradiated; and a control member configured to enable the X-ray irradiation region controller to control the X-ray irradiation region, based on the image of the X-ray irradiation region displayed in the display member, wherein the display member displays the image of the X-ray irradiation region as a first image in the image of the object output from the camera such that the first image of the X-ray irradiation region overlaps the image of the object, and wherein the display member further displays a second image of the X-ray irradiation region, in addition to the first image of the X-ray irradiation region to be overlapped with the image of the object, such that the first image of the X-ray irradiation region overlapped with the image of the object is changed according to a change of the second image of the X-ray irradiation region.