A planar ThermoElectric Generator (TEG) containing five thermocouples based on nanostructured metal-oxide elements wired electrically in series and thermally in parallel has been designed and fabricated. The thermoelectric elements consist of ZnO (n-type) and CuO (p-type) bundles of quasi-monodimensional nanowires deposited utilizing shadow masks. The TEG has been experimentally characterized, confirming feasibility of fabricating planar thermoelectric devices based on metal-oxide nanowires with the future aim to powering portable electronics and autonomous sensors and microsystems.