A display device includes: a substrate on which a display unit is formed and an encapsulation unit for sealing the substrate; a touch screen panel formed on the encapsulation unit; a window cover provided on the touch screen panel; an alignment key for aligning positions of the display panel and the window cover; and a sealing portion disposed between the substrate and encapsulation unit. An area expansion portion is formed in a position of the sealing portion corresponding to the alignment key.