1. A flexible display device comprising:a display substrate comprising a plurality of protrusion portions and a plurality of recess portions at one surface thereof and curved surfaces respectively extending between ones of the plurality of protrusion portions toward a center of an adjacent one of the recess portions;
a pixel unit configured to emit light on the display substrate, the pixel unit comprising a plurality of pixels;
a first wiring coupled to the pixel unit and elongated in a first direction; and
a second wiring elongated in a second direction crossing the first direction,
wherein the plurality of pixels are disposed on the plurality of protrusion portions between the plurality of recess portions, and
wherein a width of each of the recess portions is larger than a width of each of the pixels.