A display device includes a substrate of a display panel, including: a display area and a non-display area, an upper surface and a lower surface each in the display area and the non-display area, and side surfaces connecting the upper and lower surfaces to each other; a signal line on the upper surface of the substrate; a circuit substrate on a side surface of the substrate; and a connection electrode on the upper surface of the substrate in the non-display area thereof, where the connection electrode electrically connects the signal line and the circuit substrate to each other. In the non-display area, the substrate further includes: a first etched portion recessed from the side surface at which the circuit substrate is disposed, and a second etched portion extending from the first etched portion toward the signal line, and the connection electrode is in the first and second etched portions.