There is disclosed a piezoelectric thin film having less non-uniform portions and holding satisfactory piezoelectric characteristics, a method of manufacturing the film, a piezoelectric element using the piezoelectric thin film, and an ink jet system recording head using the piezoelectric element. In the piezoelectric thin film of perovskite crystals formed on a substrate by a sol-gel process and represented by a general formula Pb.sub.(1-x)La.sub.x(Zr.sub.yTi.sub.1-y)O.sub.3 (where 0.ltoreq.x<1, 0.05.ltoreq.y.ltoreq.1), a film thickness of the thin film is 1000 nm or more and 4000 nm or less, and a difference between a maximum value and a minimum value of y in an arbitrary portion of the thin film is 0.05 or less.