A keyboard apparatus which is capable of imparting a natural key depression feeling with a definite and positive load change, with a simplified construction. A key touch feeling-imparting mechanism imparts a predetermined key touch feeling to a key when it is depressed. The key touch feeling-imparting mechanism is comprised of a receiving part provided on a support member, and an elastic engaging unit that has one end thereof held by a key operating part of an associated key and another end thereof slidably engaged with the receiving part. The elastic engaging unit is disposed such that the elastic engaging unit is bent during a forward stroke of key depression caused by a key depressing operation to give a reaction force to the associated key, and the elastic engaging unit suddenly decreases in an amount of bend thereof due to a change in a sliding frictional state between the other end thereof and the receiving part during the forward stroke of key depression, to thereby decrease the reaction force given to the associated key.