In this thesis, I present an extensive study of thermally evaporated tungsten oxide cluster ultrathin films, ranging from submonolayer coverages to few-layer structures on Cu(110) and Cu(110)-(2x1)O substrates in ultra-high vacuum. A wide range of experimental and theoretical methods were applied. Structural investigations were performed using low energy electron diffraction and scanning tunneling microscopy at temperatures between 15K and 300K. The electronic structure was investigated using photoelectron spectroscopy, angle integrated as well as angle resolved, combined with X-ray absorption spectroscopy of the near edge region, partially carried out with synchrotron radiation. The phonon structure of the tungsten oxide films was studied with high resolution electron energy loss spectroscopy. The experimental data were complemented by density functional theory calculations. The adsorption and self-assembly of cyclic (WO3)3 clusters were investigated over a wide temperature range from 15K to 975K, starting from a few clusters up to several layers. At increased coverage and temperature, the self-assembly of the clusters into well-ordered one and two-dimensional structures was observable on both, the Cu(110) and the Cu(110)-(2x1)O substrate. The (WO3)3 clusters on Cu(110) revealed a complex phase diagram with hexagonal and rectangular structures coexisting. Using Cu(110)-(2x1)O as substrate revealed a single well ordered structure, which was investigated in detail. The combination of experimental and theoretical techniques revealed the formation of a ternary oxide phase, a two-dimensional copper tungstate CuWO4.