A nanocrystal display device includes a plurality of pixels; a gate line extended in a row direction; a data line extended in a column direction; and a second insulating layer on the data line. Each pixel includes first and second pixel areas adjacent to each other in the column direction; first and second pixel electrodes on the second insulating layer of the first and second pixel areas; a first black matrix on the second insulating layer, and having a step difference greater than that of the first and second pixel electrodes; a common electrode extended in the row direction, contacting the first black matrix and spaced apart from the second insulating layer in the first and second pixel areas, and a tunnel-shaped cavity between the common electrode, the first black matrix and the second insulating layer; and a liquid crystal layer in the tunnel-shaped cavity.