A method for forming a dielectric film using a dielectric film forming apparatus including a vacuum chamber; a target formed of lead zirconate titanate disposed inside the vacuum chamber; a substrate holding pedestal for holding substrate, disposed in a position facing the target; a substrate heating portion for heating the substrate supported by the substrate holding pedestal; a sputtering power supply for applying a voltage to the target; a sputtering gas introduction unit for introducing sputtering gas into the vacuum chamber; a deposition preventive plate disposed in a position where particles discharged from the target adhere inside the vacuum chamber; and a deposition preventive plate heating portion for heating the deposition preventive plate, the method including step of preliminarily determining a film forming temperature, film forming step including setting a temperature of the substrate to be the film forming temperature, applying a voltage to the target from the sputtering power supply, and sputtering the target, forming a PZT thin film on the substrate and the deposition preventive plate, the method further comprising the steps of: introducing sputtering gas into the vacuum chamber from the sputtering gas introduction unit, heating the deposition preventive plate to a temperature higher than a film forming temperature, emitting vapor of PbO from the PZT thin film adhered to the deposition preventive plate and forming a seed layer including Pb and O on the substrate; and wherein in the film forming step, the PZT thin film is formed on the seed layer and the deposition preventive plate. a vacuum chamber; a target formed of lead zirconate titanate disposed inside the vacuum chamber; a substrate holding pedestal for holding substrate, disposed in a position facing the target; a substrate heating portion for heating the substrate supported by the substrate holding pedestal; a sputtering power supply for applying a voltage to the target; a sputtering gas introduction unit for introducing sputtering gas into the vacuum chamber; a deposition preventive plate disposed in a position where particles discharged from the target adhere inside the vacuum chamber; and a deposition preventive plate heating portion for heating the deposition preventive plate, the method including step of preliminarily determining a film forming temperature, film forming step including setting a temperature of the substrate to be the film forming temperature, applying a voltage to the target from the sputtering power supply, and sputtering the target, forming a PZT thin film on the substrate and the deposition preventive plate, the method further comprising the steps of: introducing sputtering gas into the vacuum chamber from the sputtering gas introduction unit, heating the deposition preventive plate to a temperature higher than a film forming temperature, emitting vapor of PbO from the PZT thin film adhered to the deposition preventive plate and forming a seed layer including Pb and O on the substrate; and wherein in the film forming step, the PZT thin film is formed on the seed layer and the deposition preventive plate. introducing sputtering gas into the vacuum chamber from the sputtering gas introduction unit, heating the deposition preventive plate to a temperature higher than a film forming temperature, emitting vapor of PbO from the PZT thin film adhered to the deposition preventive plate and forming a seed layer including Pb and O on the substrate; and wherein in the film forming step, the PZT thin film is formed on the seed layer and the deposition preventive plate.