The present specification relates to a portable device that controls a photography mode, and a control method therefor. A control method of a portable device that controls a photography mode according to an embodiment may comprise the steps of: detecting a first marker at a first distance from the portable device and a second marker at a second distance using at least one of a first camera unit and a second camera unit; and executing a photography mode that captures an image. A 2D photography mode is executed if the first distance of the detected first marker and the second distance of the detected second marker are effectively the same; and a 3D photography mode is executed if the first distance of the detected first marker and the second distance of the detected second marker are different, wherein the 3D photography mode may be a mode that generates a 3D image using binocular disparity of the first camera unit and the second camera unit.