A flexible touch screen panel includes a window substrate, a polarizing functional layer, sensing patterns and sensing lines. The window substrate is flexible. The polarizing functional layer is attached on a first surface of the window substrate, and is divided into an active area and an inactive area positioned outside of the active area. The sensing patterns are formed in the active area on a first surface of the polarizing functional layer. The sensing lines are formed in the inactive area on the first surface of the polarizing functional layer, and are connected to the sensing patterns. In the touch screen panel, the polarizing functional layer has a laminated structure in which a polarizer and a retardation compensation film are attached on the first surface of the window substrate.