A keyboard unit includes: a key; a displacement member driven directly or indirectly with the key by a pressing operation to be moved; object detection sections including: detection sections, states of which become state change detection state when detecting changes instates of the key and the displacement member; and a generator, in a case that states of all the object detection sections become the state change detection state in the forward stroke of a key pressing operation, obtaining detection results of at least two sets of the detection sections, each set including two object detection sections, selecting at least one of the obtained detection results of the at least two sets of the detection sections, and generating sound generation indication information based on the selected at least one of the detection results.