A display device comprises a first substrate comprising an opening, a pad part on the first substrate and exposed through the opening, a second substrate on the pad part and comprising a first contact hole, a first connection line on the second substrate, and inserted into the first contact hole to be connected to the pad part, a second connection line in a layer between the second substrate and the first connection line and connected to the first connection line, a pixel circuit electrically connected to the second connection line, a driver substrate inserted into the opening of the first substrate, and comprising a base part below the pad part and having a side surface tapered from a top surface, and a lead line extending on a bottom surface and the side surface of the base part, and a contact portion electrically connecting the pad part to the lead line.