A piezoelectric-driven MEMS element includes a substrate, a beam, a fixed portion, a fixed electrode portion and a power source. The beam is provided with a lower electrode film, a lower piezoelectric film, a middle electrode film, an upper piezoelectric film and an upper electrode film. The fixed portion fixes one end of the beam onto the substrate so as to hold the beam with a gap above the substrate. The fixed electrode portion has a capacitive gap between the fixed electrode portion and the other end of the beam. In addition, at least one or two of the lower electrode film, the middle electrode film and the upper electrode film is thicker than the rest thereof.