A piezoelectric thin-film resonator and the filter having these

A piezoelectric thin-film resonator includes a lower electrode that is provided on a substrate, a piezoelectric thin film which is provided on the lower electrode, and an upper electrode provided on the piezoelectric thin film. A membrane region is defined by a region where the upper electrode and the lower electrode overlap each other to define therebetween to arrange a piezoelectric thin film is sandwiched, and which has an elliptical shape, and the lower electrode is also at an outer side of the membrane region in a region provided, in which neither an extraction electrode of the upper electrode, an extraction electrode or the lower electrode is provided.