A micro electro-mechanical system (MEMS) switch includes an active device, an immovable metal layer and a movable metal layer is provided. The immovable metal layer is disposed on the active device and the movable metal layer is disposed above the immovable metal layer. Accordingly, an insulating cavity is formed between the immovable metal layer and the movable metal layer. Further, the active device is capable of driving the movable metal layer. Compare to thin film transistor, since the operation performance of the MEMS switches would not affected by carrier mobility and on-off current ratio, display performance of the display device can be easily improved.