A keyboard device includes an operation surface. One long side of the operation surface is referred to as a proximal side, which nears a user operating the keyboard device; and the other long side is referred to as a distal side. A key unit is positioned on the proximal side, wherein the key unit includes a plurality of keys. A camera module is positioned on the distal side. An angle between a border of a field of view of the light sensor and the operation surface is set at a particular angle thus user's hand lays outside the field of view of the light sensor when the user is manipulating the key unit.