A method of manufacturing a flexible display device for sensing bending that includes forming a lower electrode layer, which includes a plurality of lower electrodes spaced apart from each other on a substrate, forming an insulation layer on the lower electrode layer, forming holes in the insulation layer to expose at least a part of each of the plurality of lower electrodes, and forming an upper electrode layer, which includes a plurality of upper electrodes that are spaced apart from each other on the insulation layer and that fill the holes in the insulation layer. At least two conductive units including the lower electrode layer, the insulation layer, and the upper electrode layer are formed to face each other on a substrate of a non-display unit that is arranged near a boundary of the display device.