A substrate 121 has a reflecting layer 122 formed thereon, the reflecting layer 122 having a mirror surface on the substrate 121 side. When light is emitted from light transmitting regions 120T, a display mode is achieved in which a desired display mode is performed according to the state of the voltage applied to a liquid crystal 130. Also, when the voltage applied to the liquid crystal 130 is less than the threshold value, and a backlight 140 is turned off to substantially cut off light transmitted through all light-transmitting regions 120T, a mirror mode is set in which the entire surface is seen as a mirror surface by the mirror surface of the reflecting layer 122. Therefore, the display screen of the electro-optical device 100 can be used as a mirror.