A keyswitch structure includes a base plate, a keycap, and a support mechanism. The support mechanism supports the keycap above the base plate. An outer support of the support mechanism includes a reinforcing body and a connecting structure fixed on the reinforcing body. The outer support is connected to the base plate and the keycap through the connecting structure. In an embodiment, the reinforcing body has two openings. Two inner supports of the support mechanism are pivotally connected to the connecting structure and are located in the two openings, respectively. In another embodiment, the reinforcing body as a whole extends along a plane. The reinforcing body has a bent fringe, which is inserted into the connecting structure and is not perpendicular to the plane.