A portable electronic device is provided which an operator (photographer) has not an abnormal but favorable feeling from a design (aesthetic) viewpoint and which enables the operator to know an area in which a photograph can be successfully taken or a position of a subject to be photographed. A control section has an auxiliary display section display present time, notification of arrival of data and/or messages, or a like when no photograph is taken. When the operator presses down a photographing mode selecting key, the control section controls a liquid crystal panel so that its all pixels are put into a light transmitting state and causes reflected light from a mirror reflecting plate to be visually viewed by the operator. That is, the auxiliary display section operates as the mirror to look therein at an image of a subject to be photographed. The operator, if wishing to take a photograph of himself/herself, holds a portable cellular phone and directs a camera lens toward himself/herself, and corrects a posture of the portable cellular phone so that his/her face may be looked in such a manner that has a desired size or a desired position in the auxiliary display section operating as the mirror. After the operator has determined photographic composition of the subject, the operator presses down the shutter button.