The present invention is to provide a piezoelectric element, a method of manufacturing the same, a liquid-jet head, a method of manufacturing the same, and a liquid-jet apparatus, all of which prevent an inter-layer detachment in a lower electrode. A method of manufacturing a piezoelectric element, comprising the steps of: forming, on a substrate, a lower electrode configured of a plurality of layers which includes a metal layer with a limit thickness of 20 nm at least in its uppermost layer, the metal layer essentially containing iridium; forming a multi-layered piezoelectric layers by means of performing a piezoelectric film forming step a plurality times, the piezoelectric film forming step including an applying step of applying a piezoelectric precursor film onto the lower electrode, a drying step of drying the piezoelectric precursor film which has been applied thereon through the applying step, a degreasing step of degreasing the piezoelectric precursor film which has been dried through the drying step, and a baking step of making the piezoelectric precursor film, which has been degreased through the degreasing step, into a piezoelectric film by baking and crystallizing the piezoelectric precursor film; and forming an upper electrode on the piezoelectric layer.