A device of balancing lever in a multiplicative key used in a keyboard comprises a cap, a base with a pair of guiding elements, a bridge support, and a balancing lever. Each gliding element has a hole, both ends of the balancing lever are symmetrically bent upward at a suitable angle. The two ends of the balancing lever pass through the holes on the pair of guiding elements and are supported therein at fixed positions such that the cap is kept in a stable orientation when pressed on.