Rapid scanning Fourier Transform Infrared Spectroscopy has been applied to obtain spectra from aluminum anodic coatings. The spectra were recorded with different measuring techniques e.g. transmission, absorption-reflection, and ATR in the far and middle IR regions. Infra red light polarization has also been used. From the experimental data vibrational band assignments have been made. Based on these assignments a coating structure and coating formation mechanism has been proposed.