PIEZOELECTRIC THIN FILM FILTER

A piezoelectric thin film filter where insertion loss and deterioration of sharpness of a shoulder are suppressed and ripples in a pass band can be suppressed is provided. In first and second vibration parts (20s) and (20p), a piezoelectric thin film (16) is arranged between a pair of electrodes (15s) and (17s); (15p) and (17p) along one main face (12a) of a substrate (12), and they are acoustically separated from the substrate (12). A first resonator (S1) is brought into contact with one electrode (17s) forming not less than a half of whole length of an outer periphery of the first vibration part (20s) if it is viewed from a thickness direction and an additional film (22) is arranged outside. In a second resonator (P1), an outer shape of the second vibration part (20p) is polygonal and respective sides of a polygon are nonparallel to the other sides if viewed from the thickness direction.