A label having an identifier 41L is applied to the upper left corner of the key top of each character key in a left hand region of a keyboard device. A label having an identifier 41R is applied to the upper right corner of the key top of each character key in a right hand region. The identifier 41L is a mark of a reversed L shape and the identifier 41R is a mark of a mirror image pattern of the identifier 41L. Further, different colors are applied to the identifiers 41L and 41R depending on regions for individual fingers. As a consequence, the identifiers 41L and 41R have a function to visually display information representing which hand is to be used to press a key and information representing which finger is to be used to press the key. The keyboard device enables a user to naturally understand the arrangement of the keys and the use of the fingers.