US Patent 10347223 Keyboard device and keyboard instrument

A keyboard device where at least one of a transmission rail and a hammer rail is favorably supported, and a keyboard instrument including the keyboard device are provided. A transmission support pole for supporting the transmission rail and a hammer support pole for supporting the hammer rail are each arranged in a gap between two keys adjacent to each other among a plurality of keys, arranged in a hole provided in at least one of the plurality of keys, or arranged at a position corresponding to a key support shaft which supports at least one of the plurality of keys. As a result, at least one of the transmission support rail and the hammer support rail is favorably supported.