Providing a mechanism which can eliminate an influence of residual strain in a piezoelectric thin film, having excellent piezoelectric strain characteristics. A thin film piezoelectric component is provided having low residual strain at its grain boundary (14A) between the piezoelectric PZT film (15) and its platinum electrode (14), even after performing polarization processing (poling) on the piezoelectric thin film component. The width of the grain boundary is 5 nm or less. The crystal grain boundary is a discontinuous layer which does not continue the orientation of adjacent crystal grains.