An X-ray apparatus includes an X-ray radiator configured to radiate an X-ray, and a controller acquiring orientation information of the X-ray radiator and orientation information of at least one X-ray detector, selecting the at least one X-ray detector based on the orientation information of the X-ray radiator and the orientation information of the at least one X-ray detector, and determining a power mode of the selected X-ray detector to be a power consumption mode and a power mode of an X-ray detector that is not selected, to be a power save mode.