Key switch and keyboard

A key switch including a plurality of key tops coupled with each other in an independently movable manner and a switching mechanism arranged close to the key tops and including plural sets of electric contacts. The switching mechanism is capable of opening and closing any one of the plural sets of electric contacts in connection with individual movements of the key tops. A keyboard having a plurality of key switches includes a casing for accommodating the key switches with the key tops thereof being at least partially exposed, and a connecting section joined to the casing and capable of electrically connecting the key switches with a portable information apparatus. The casing is capable of detachably supporting the portable information apparatus through the connecting section.