An Ir film was grown heteroepitaxially on the epitaxial (100)ZrN film deposited on the (100)Si substrate by sputtering. Further, we obtained a heteroepitaxial (001)PZT film on the epitaxial (100)Ir/(100)ZrN/(100)Si substrate structure by reactive sputtering. The crystallographic relationship was cube-on-cube. The polarization-electric field hysteresis loop of the 300-nm-thick epitaxial PZT film with a top electrode of IrO2 showed a saturated square shape at an ac amplitude of 5V, and the remanent polarization, 2Pr, and coercive field, 2Ec, were 60 μC/cm 2 and 80 kV/cm, respectively. The Pr was not reduced up to 5×1010 switching cycles with a ±10 V bipolar pulse train. The leakage current of the PZT film at +5 V and –5 V was about 8.0× 10−8 and 2.5 ×10−7 A/cm2, respectively.