1. A photographing device comprising: a photographing unit; an image processor which separates an object from a first photographing image obtained by the photographing unit; a display which displays a background live view obtained by superimposing the separated object on a live view of a background; and a controller which obtains a second photographing image corresponding to the live view of the background when a command to shoot the background is input, and generates a composite image based on the separated object and the second photographing image.