The fundamental development on the design of novel self-powered ozone sensing elements operating at room temperature based on p-type metal oxides pave the way to a new class of low cost highly promising gas sensing devices. Here, we synthesize a p-Type Cu2O nanocubes by a simple solution-based method and tested as self-power ozone sensing element, at room temperature (25°C) for a first time. High crystalline Cu2O nanocubes with 30nm size, were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM). Self – powered sensing elements of Cu2O nanocubes has been succesfully fabricated by deposit of Cu2O nanocubes on interdigitated electrodes (IDE’s) consisting of two connection tracls with 500digits and a gap of 5μm in order to investigate their response to ozone at room temperature. The experimental results showed that the use of nanocubes as sensing element was suitable for detecting ultra – low concentrations of O3 down to 10 ppb at room temperature with very high sensitivity (28%) and very low response/recovery time. The reversible sensing process to the relatively weak binding of O3 species by trapping sites on Cu2O facets with increased oxygen content calculated by using density functional theory calculations.