A display device is capable of preventing damage to a signal line in a dehydrogenation process of a semiconductor layer and to a method of manufacturing the display device, the display device including: a substrate; at least one switching element on the substrate; a pixel electrode connected to the at least one switching element; a semiconductor layer on the substrate, the semiconductor layer providing a channel area of the at least one switching element; an insulating layer on the semiconductor layer; and a conductive layer connected to the semiconductor layer through a contact hole of the insulating layer. The insulating layer has a groove that overlaps the semiconductor layer and surrounds the conductive layer in the contact hole.