The present invention provides a piezoelectric element having consistently high piezoelectric characteristics, and a liquid jetting head in which this element is used. A bottom electrode 42 (which contains Ir), a Ti layer of no less than 4 nm and no more than 6 nm, a piezoelectric thin film 43, and a top electrode 44 are sequentially layered on a ZrO.sub.2 film 32. The piezoelectric thin film 43 has the degree of orientation in the 100 plane, as measured by the X-ray diffraction wide angle technique, is 70% or greater, the degree of orientation in the 110 plane is 10% or less, and the degree of orientation in the 111 plane constitutes the remaining balance. Such piezoelectric thin film 43 can be obtained stably with good reproducibility by keeping the humidity of the environment for forming the piezoelectric thin film at 30% Rh or less.