A display device in which damage and carbonization of a display substrate is substantially minimized and a method of manufacturing the display device are provided. A display device includes: a substrate including a first area having a first thickness and a second area having a second thickness which is different from the first thickness; a display layer at the first area of the substrate; and a functional member on the display layer at the first area. The first area and the second area are arranged along a first direction, the substrate includes a protruding portion at the second area, and the protruding portion includes a side portion having an inclination of about 5 degrees or more with respect to the first direction toward a second direction which intersects the first direction.