Recently, the emergence of conductive metal organic frameworks (MOFs) has given great prospects for their applications as active materials in electronic devices. In this work, a high-quality, freestanding conductive MOF membrane was prepared by an air liquid interfacial growth method. Accordingly, field-effect transistors (FETs) possessing a crystalline micro porous MOF channel layer were successfully fabricated for the first time. The porous FETs exhibited p-type behavior, distinguishable on/off ratios, and excellent field-effect hole mobilities as high as 48.6 cm(2) V-1 s(-1), which is even comparable to the highest value reported for solution processed organic or inorganic FETs.