A display device includes: a substrate including an alignment area in a non-display area, and a display area including a plurality of material layers on the substrate; in the alignment area, a plurality of keys including a first alignment key and a second alignment key. Each alignment key includes a light blocking pattern, a layer pattern and a display pattern. The position of the display pattern within the first alignment key is different from the position of the display pattern within the second alignment key, the layer pattern of the alignment key and one material layer among the plurality of material layers are respective portions of a same material layer on the substrate, and the layer pattern of the first alignment key and the layer pattern of the second alignment key are respective portions of different material layers among the plurality of material layers on the substrate.