An electronic keyboard instrument having a keyboard provided with a plurality of keys, a first and a second switches provided corresponding to each key of the keyboard and being sequentially turned on at a time interval corresponding to a key depression speed of the keyboard, a counting unit for counting a count value corresponding to the time interval during which the first and the second switches are sequentially turned on, a correcting unit for correcting the count value or a value corresponding to the count value based on a variation of the time interval, and a velocity conversion unit for converting the corrected value into a velocity, is provided.