Organic electronic devices using a pentacene have improved importantly in the last several years. We fabricated pentacene organic thin-film transistors (OTFTs) with dielectric SiO2 and ferroclectric Pb(Zr-0.3,Ti-0.7)O-3 (PZT) gate insulators. The organic devices using SiO2 and PZT films had\ 2 the field-effect mobility of approximately 0. 1 and 0.004 CM2/Vs, respectively. The drain current in the transfer curve of pentacene/PZT transistors showed a hysteresis behavior originated in a ferroelectric polarization switching. In order to investigate the polarization effect of PZT gate dielectrics in a logic circuit, the simple voltage inverter using SiO2 and PZT films was fabricated and measured by an output-input measurement. The gain of inverter at the poling-down state was approximately 7.2 and it was three times larger than the value measured at the poling-up state. (c) 2006 Elsevier B.V. All rights reserved.