To provide a keyboard device for which the movement of a key top by the operation of an operator is natural to the structure of a hand of a person.

The keyboard device 1 includes a keyboard body part 11, a predetermined number of main keys 12 and a predetermined number of sub keys 13. On the main keys 12, a key top character or symbol is displayed. The sub keys 13 are keys other than the respective main keys 12 such as ten keys or a shift control key. The respective main keys 12 and the respective sub keys 13 are arranged on the basis of a predetermined keyboard array on the keyboard body part 11. Since the respective main keys 12 are operated by the pointing fingers, middle fingers, ring fingers and little fingers of a right hand and a left hand, they are constituted of a slide type key switch device to be turned from a non-active mode to an active mode when an operators pulls the key top 12a of the main key 12 from the back for the operator to the front limit position.