A tuning device that facilitates the checking of the pitch of each sound is provided. The tuning device includes a pitch name display means including display positions that are arranged in a pitch order respectively corresponding to pitch names constituting an octave. A reference display position is lighted solely when the pitch of an input sound is in an in-tune state, namely, a difference between the reference pitch and the pitch of the input sound is in a range of ±α (α>0). When the pitch of the input sound is outside a predetermined range, the reference display position and an adjacent display position are both lighted in a way that the reference display position gradually becomes darker while the adjacent display position gradually becomes brighter as an absolute value of the difference (deviation degree of the input pitch relative to the reference pitch) increases.