For manganese oxides a strong variety in there physical and chemical properties is expected depending on the filling of the manganese 3d-orbital. They are discussed as catalysts, as sensors, and as electrode material in lithium batteries. Three different manganese oxides have been prepared on Pt(111). High resolution electron energy loss spectroscopy (HREELS) has been used to get informations about coverage dependent vibrational properties of the MnO films. The structure has been characterized by low electron energy diffraction (LEED) and the thermal stability of the manganese oxide films was investigated by temperature programmed desorption (TPD). The manganese oxides have been identified as MnO(100), as Mn3O4, and as oxygen terminated MnO(111). The oxides can clearly be distinguish by there HREEL-spectra. Therefore this informations can be used as a reference for the investigation of chemical reactions of the manganese oxides. I this way the thermal and chemical induced phase transitions between these manganese oxides (oxidation and reduction) has been investigated. Additional the thickness dependent vibrational spectra of MnO(100) have been compared to different theoretical models.