<p>PURPOSE: A flexible display device is provided to improve the connection of a circuit terminal to a pad by using a stiffener having enforcement lines. CONSTITUTION: A stiffener(160) is arranged along one edge of a flexible printed circuit board. The stiffener includes enforcement lines(161) for preventing the thermal deformation of the flexible printed circuit board. The enforcement lines are separated from each other in the X direction of the flexible printed circuit board. A space(162) is formed between adjacent enforcement lines. A pad for inputting an electric signal to a display unit is formed in the flexible printed circuit board.</p>
