A keyswitch includes a casing, a key cap and a support device rotatably disposed between the key cap and the casing. One of the casing and the key cap has a first magnetic area and the support device has a second magnetic area corresponding to the first magnetic area. When the key cap is not pressed, a magnetic attraction force between the first and second magnetic areas keeps the key cap at a non-pressed position. When the key cap is pressed by an external force such that the second magnetic area moves away from the first magnetic area, the key cap moves from the non-pressed position toward the pressed position. When the external force is removed, the second magnetic area moves toward the first magnetic area due to the magnetic attraction force such that the key cap moves from the pressed position toward the non-pressed position.