To provide a photographing device which easily determines an optimum compositional arrangement, and also to provide its control method.

When a print paper 200 of an aspect ratio 3:1 is set under the condition that the printing aspect ratio is regular 4:3, and the printing aspect ratio is changed to 3:1, the information is outputted to a system controller 115. The system controller 115 outputs a control signal to a display circuit 118 so that the aspect ratio becomes 3:1. The display circuit 118 conducts aspect ratio change processing in which a screen display aspect ratio to be displayed on an image display LCD 15 becomes the aspect ratio 3:1. The aspect ratio change processing is conducted by applying black mask processing to upper/lower portions of a display screen of the image display LCD 15 so that the aspect ratio in the screen becomes seemingly the same as the aspect ratio 3:1 of the print paper.