A display device including a first substrate, a second substrate, a display element layer, a non-transparent structure, an optical guiding structure and a reflective layer is disclosed. The second substrate is disposed opposite to the first substrate adjacent to a display surface of the display device. The display element layer is disposed between the first and the second substrates. The non-transparent structure, located between the optical guiding structure and the display element layer, defines at least one opening of the display device. The optical guiding structure corresponds to the one opening. The optical guiding structure includes a plurality of insulating structures each having a first surface adjacent to the non-transparent structure and side surfaces connected to the first surface. The reflective layer is disposed on the side surfaces. The ambient light entering via the second substrate is reflected by the reflective layer and exists via the opening.