A keyboard including a substrate and a key structure is provided. The key structure is disposed on the substrate and includes a keycap, an antenna, and a sensor. The keycap is disposed on the substrate, and a length of the keycap is greater than a width of the keycap. The antenna is disposed on a back surface of the keycap facing toward the substrate. The sensor is disposed below the keycap and is electrically connected with the antenna.