An operation input unit includes a board unit including a switch, and a base. An external force application portion moves by a button portion being pushed, and changes an open or closed state of the switch by varying an external force acting on the board unit in accordance with the movement. A board deflection portion forms a space between the board deflection portion and the base in a state that the button portion is not pushed, and deflects toward a movement direction of the external force application portion by the external force application portion moving by the pushing of the button portion.