The annealing properties on the infrared absorption of 6oCo gamma induced thin layer on the surface of germanium single crystal have been studied. Both isochronal and isothermal annealing were using air as heat transfer medium. The absorption bands associated with the induced thin layer can be removed under prelonged annealing. But an absorption band with peak at 11.6μ associated with the gamma-induced surface layer on germanium has been observed after isochronal annealing and isothermal annealing at temperature higher than 215°C. The intensity of the 11.6μ band is proportional to the initial annealed temperature.