A method of controlling an electronic device having a transparent display. The method includes controlling the electronic device to provide a first image through an optical display mode operation of the transparent display in which light incident from an object is transmitted, controlling the electronic device to acquire a second image through a video display mode operation of the transparent display in which an image captured from the object is displayed, and selectively displaying the first and second images using the transparent display by a mixing, by the electronic device, of the first and second images. The mixing may be dependent on a distance between the electronic device and the object or a display ratio between the first and second images. An image for an object may be displayed in a region of interest and an image for another object in a remaining region.