Thin films of copper oxides were prepared by reactive magnetron sputtering and structural, morphological, chemical, and electronic properties were analyzed using x-ray diffraction, atomic force microscopy, in situ photoelectron spectroscopy, and electrical resistance measurements. The deposition conditions for preparation of Cu(I)-oxide (Cu{sub 2}O) are identified. In addition, the interface formation between Cu{sub 2}O and Sn-doped In{sub 2}O{sub 3} (ITO) was studied by stepwise deposition of Cu{sub 2}O onto ITO and vice versa. A type II (staggered) band alignment with a valence band offset {Delta}E{sub VB} 2.1-2.6 eV depending on interface preparation is observed. The band alignment explains the nonrectifying behavior of p-Cu{sub 2}O/n-ITO junctions, which have been investigated for thin film solar cells.