A keyboard device for an electronic keyboard instrument, which has a simple construction and can be manufactured at relatively low costs, and is capable of providing let-off feeling closely analogous to the let-off feeling of an acoustic piano. The keyboard device comprises keys, hammers each of which has an engaging part and pivotally moves in accordance with pivotal motion of an associated key, an unmovable holder, and let-off members each formed of an elastic material, for temporary engagement with the engaging part of an associated hammer during each of key depression and key release, to impart let-off feeling to touch feeling of an associated key during key depression. Each let-off member extends from the holder to a pivotal path along which the associated hammer performs pivotal motion, and is compressed during key depression and deflected during key release by engagement with the engaging part.