A computed tomography apparatus comprising a gantry including a first rotation device and a second rotation device which have a ring shape, share an axis of rotation, and are rotatable independently of each other; a transfer unit (150,550) on which a subject may be loaded; a plurality of light sources (531, 533, 535) provided at regular intervals on the first rotation device and configured to emit X-rays to a subject; a detector (140, 540) provided on the second rotation device and configured to detect X-rays passing through the subject; and one or more processors, wherein the one or more processors are configured tc control the transfer unit (150,550) to be moved by a predetermined distance or at a predetermined speed in a direction of an axis of rotation of the gantry; rotate the first rotation device in a first rotation direction by an angle of rotation determined based on a total number of the plurality of light sources (531, 533, 535); emit X-rays to the subject by using at least one of the plurality of light sources (531, 533, 535) and detect X-rays passing through the subject by the detector (140, 540) during the rotation of the first rotation device in the first rotation direction; rotate the first rotation device by the determined angle of rotation in a second rotation direction opposite to the first rotation direction; and emit X-rays to the subject by using at least one of the plurality of light sources (531, 533, 535) and detect X-rays passing through the subject by the detector (140, 540) during the rotation of the first rotation device in the second rotation direction, wherein the detector (140, 540) is configured to surround inner sides of the second rotation device, and the one or more processors are configured to control the plurality of light sources (531, 533, 535) to alternately emit X-rays to the subject in units of a unit angle in a predetermined order during the rotation of the first rotation device in the first rotation direction or the second rotation direction. a gantry including a first rotation device and a second rotation device which have a ring shape, share an axis of rotation, and are rotatable independently of each other; a transfer unit (150,550) on which a subject may be loaded; a plurality of light sources (531, 533, 535) provided at regular intervals on the first rotation device and configured to emit X-rays to a subject; a detector (140, 540) provided on the second rotation device and configured to detect X-rays passing through the subject; and one or more processors, wherein the one or more processors are configured tc control the transfer unit (150,550) to be moved by a predetermined distance or at a predetermined speed in a direction of an axis of rotation of the gantry; rotate the first rotation device in a first rotation direction by an angle of rotation determined based on a total number of the plurality of light sources (531, 533, 535); emit X-rays to the subject by using at least one of the plurality of light sources (531, 533, 535) and detect X-rays passing through the subject by the detector (140, 540) during the rotation of the first rotation device in the first rotation direction; rotate the first rotation device by the determined angle of rotation in a second rotation direction opposite to the first rotation direction; and emit X-rays to the subject by using at least one of the plurality of light sources (531, 533, 535) and detect X-rays passing through the subject by the detector (140, 540) during the rotation of the first rotation device in the second rotation direction, wherein the detector (140, 540) is configured to surround inner sides of the second rotation device, and the one or more processors are configured to control the plurality of light sources (531, 533, 535) to alternately emit X-rays to the subject in units of a unit angle in a predetermined order during the rotation of the first rotation device in the first rotation direction or the second rotation direction.