A keyboard device includes a key structure, a base plate and a soft fixing element. The key structure includes a keycap and a stabilizer bar. The stabilizer bar is connected with the keycap and the soft fixing element. The soft fixing element is disposed on the base plate. The soft fixing element has an accommodation space. The stabilizer bar is inserted into the accommodation space, so that the stabilizer bar is connected with the base plate. After a fixing post of the soft fixing element is penetrated through a fixing hole of the base plate, the fixing post is thermally treated to form the hot melt fixing structure. Consequently, the soft fixing element is firmly fixed on the base plate. Since the metallic stabilizer bar and the metallic base plate are separated by the soft fixing element, the keyboard device is capable of reducing noise.