The dependence of the chemical states of the constituent elements of a PZT thin film prepared by RF magnetron co-sputtering using ceramic PZT and metallic Pb dual target materials on the Ar+ etching time was studied using XPS. The metallic Pb, lead oxide and Pb in PZT led to the different binding energies of the Pb lines. The intensity of binding energy of metallic Pb relative to that of bulk Pb increased with the depth of the film. The peak position and the line shape of the O1s electron was associated with the different binding energies of oxygen, which interacts with Pb and Ti and Zr atoms to form the metal oxides, and the softening of the O1s bonds by the bonding interaction in Ti–O, Zr–O and Pb–O. The broad Ti2p3/2 line in the PZT film could has been associated with the various charge state of Ti and no spectral changes of Ti2p and Zr3d were observed as the Ar+ ion sputtering time was increased.