To provide a portable electronic device monitor which is a horizontal electric field liquid crystal display device and which is capable of clear display even outdoors. A reflective electrode is provided in a horizontal electric field liquid crystal display device. By providing the reflective electrode, natural light can be reflected efficiently and clear display can be provided outdoors. In addition, by providing the reflective electrode with unevenness, reflectance can be increased. The present invention provides a horizontal electric field liquid crystal display device such as this which is capable of clear display even outdoors.