A variable capacitance device has a piezoelectric driving part, a movable electrode, a fixed electrode, a dielectric film and a driving control unit. The piezoelectric driving part has a piezoelectric film, an upper electrode disposed on a top surface of the piezoelectric film, a lower electrode disposed on an undersurface of the piezoelectric film and electrode slits which separate the upper electrode and the lower electrode into two, respectively. The movable electrode is provided via the electrode slits at one end of the piezoelectric driving part. The fixed electrode is disposed opposite to the movable electrode via a gap. The dielectric film is disposed opposite to the movable electrode via the gap and provided on the fixed electrode. The driving control unit adjusts a distance between the movable electrode and the fixed electrode to reduce a fluctuation of a predetermined capacitance of a variable capacitor formed between the variable electrode and the fixed electrode.