A keyboard device includes a substrate, a keycap, a first connection member, and a first elastic arm structure. The substrate has a top surface, and the top surface has an assembling region. The keycap is disposed above the assembling region, and the keycap has a bottom surface facing the assembling region. The first connection member is connected between the keycap and the assembling region, the first connection member includes a first assembly side and a second assembly side opposite to the first assembly side, the first assembly side is pivotally connected to the bottom surface of the keycap, and the second assembly side is pivotally connected to the substrate. The first elastic arm structure includes a connection end and a free end opposite to the connection end, the connection end is connected to the first assembly side, and the free end abuts against the bottom surface of the keycap.

A button structure includes a button body, a conductive film, a circuit board, a metal elastic element and a bracket. The button body has a pressing portion. One side of an upper portion of a rear surface of the pressing portion protrudes upward to form a protruding pillar. A middle of the upper portion of the rear surface of the pressing portion extends rearward to form a triggering portion. The conductive film is disposed to an inner surface of the pressing portion, and the conductive film surrounds the protruding pillar. The circuit board has a switch corresponding to the triggering portion. One end of the metal elastic element is mounted around the protruding pillar together with the conductive film. The other end of the metal elastic element is fastened to the circuit board. The bracket is disposed to the rear of the button body.