An electronic viewfinder is configured to magnify an image and provide adjustable diopter for different observers. The electronic viewfinder includes an aperture stop, a lens group totally with positive power, and a display. The components in the electronic viewfinder are arranged sequentially between the observer and the image. The lens group is utilized to enlarge the image, and the lens group includes a first lens with positive power and a second lens with negative power. The display is for showing the image. A first planar lens is disposed between the aperture stop and the lens group. A second planar lens may be disposed between the lens group and the display. A polarizer may be arranged between the second planar lens and the lens group.