A key structure having a pressing area is provided. The key structure includes a first membrane and a second membrane. A first conductive layer and a first insulation layer are sequentially disposed on a surface of the first membrane. The first insulation layer has a first opening in the pressing area, so that a part of the first conductive layer is exposed from the first opening. The second membrane is disposed opposite to the first membrane. A second conductive layer and a second insulation layer are sequentially disposed on a surface of the second membrane facing the first membrane. The second insulation layer has a second opening, which is formed corresponding to the first opening, in the pressing area, so that a part of the second conductive layer is exposed from the second opening to face the first conductive layer in the first opening.