A flexible display device includes a supporting layer and a flexible display panel. The supporting layer has two non-folding regions and a folding region between the two non-folding regions. The folding region has a central region and two edge regions. Each of the edge regions is located between one of the two non-folding regions and the central region, and open porosities of the two edge regions are different from an open porosity of the central region. The flexible display panel is located on the supporting layer.