A transparent display device includes a base substrate having a pixel area and a transmission area, a barrier layer disposed on the base substrate, a pixel circuit disposed in the pixel area, a display structure disposed on the pixel circuit, a transmitting structure disposed in the transmission area, an adhesive layer disposed between the base substrate and the barrier layer, and between the base substrate and the transmitting structure, and a transmitting window defined in the transmission area where the transmitting structure may include a composition including silicon oxynitride, the adhesive layer may include aluminum oxide, and the transmitting window may expose a surface of the transmitting structure.