A display device includes: a display panel including a sensor area and a display area, where the display panel includes an upper surface and a lower surface opposite to the upper surface; and a discoloration sensor layer overlapping the sensor area, where discoloration sensor layer is disposed on one of the upper surface of the display panel and the lower surface of the display panel, and discolored when exposed to a target material. A first through portion is defined through the display panel from the upper surface to the lower surface of the display panel, and the discoloration sensor layer overlaps the first through portion.