A key switch device includes a key top; a link member that guides an elevating operation of the key top while being interlocking with the key top, the link member including a rotatable shaft and a sliding shaft that is connected to the key top; a membrane sheet that includes a contact that opens and closes in accordance with the elevating operation of the key top; a back plate; a housing that holds the rotatable shaft of the link member to the back plate; and a pushing unit that pushes the link member such that the sliding shaft moves away from the back plate.