An X-ray apparatus (100, 100', 100", 200) for controlling a position of an X-ray emitter , the X-ray apparatus (100, 100', 100", 200) comprising: - an X-ray emitter configured to generate X-rays and radiate X-rays to an object ; - an X-ray detector configured to detect X-rays transmitted through the object ; - a camera configured to obtain an image of the object by photographing the object , wherein the captured image is different from an X-ray image obtained by X-ray imaging the object ; characterised in that it further comprises: - a controller including an image processor configured to identify a candidate region of the object and a central point of the object by performing image processing on the obtained image, the controller being configured to: - calculate a plurality of irradiation region shapes of the X-ray emitter and positions of the X-ray emitter by matching the identified candidate region of the object and the central point of the object with a plurality of irradiation regions of the X-ray emitter and a plurality of central points of the X-ray emitter corresponding to different positions of the X-ray emitter , respectively, the candidate region being a region of the object to be X-rayed; and - generate a plurality of thumbnail images wherein each of the calculated irradiation region shapes and each of the calculated central points of the X-ray emitter to overlaps with the obtained image; wherein the X-ray apparatus (100, 100', 100", 200) further comprises: - a display configured to display the plurality of thumbnail images; - a user input receiver configured to receive a user input that selects one among the plurality of thumbnail images displayed on the display ; and - a driver configured to adjust an irradiation region of the X-ray emitter and a position of the X-ray emitter based on the user input. - an X-ray emitter configured to generate X-rays and radiate X-rays to an object ; - an X-ray detector configured to detect X-rays transmitted through the object ; - a camera configured to obtain an image of the object by photographing the object , wherein the captured image is different from an X-ray image obtained by X-ray imaging the object ; - a controller including an image processor configured to identify a candidate region of the object and a central point of the object by performing image processing on the obtained image, the controller being configured to: - calculate a plurality of irradiation region shapes of the X-ray emitter and positions of the X-ray emitter by matching the identified candidate region of the object and the central point of the object with a plurality of irradiation regions of the X-ray emitter and a plurality of central points of the X-ray emitter corresponding to different positions of the X-ray emitter , respectively, the candidate region being a region of the object to be X-rayed; and - generate a plurality of thumbnail images wherein each of the calculated irradiation region shapes and each of the calculated central points of the X-ray emitter to overlaps with the obtained image; - a display configured to display the plurality of thumbnail images; - a user input receiver configured to receive a user input that selects one among the plurality of thumbnail images displayed on the display ; and - a driver configured to adjust an irradiation region of the X-ray emitter and a position of the X-ray emitter based on the user input. <EOS>