Bismuth and bismuth oxide are materials of technological and theoretical interest because of their optical and electrical properties. Thin films of bismuth (Bi) and bismuth oxide (Bi2O3) on glass substrates were produced at room temperature using the unbalanced magnetron sputtering (UBM) technique. The microstructural characterization of samples was studied using x-ray diffraction (XRD) and confocal laser microscopy (CLM), while their elemental composition was analyzed with Auger electron spectroscopy (AES) and their optical properties with ultravioletvisible (UV/Vis) spectroscopy in the wavelength range of 500 - 1800 nm. XRD results showed that both materials have a polycrystalline character, with a rhombohedral structure for bismuth and phase for bismuth oxide. The energy band gap was 2.3 eV and 2.27 eV for bismuth and bismuth oxide, respectively.