Polytetrafluoroethylene powder (PTFE) was exposed to electron beam radiation in presence of air. The irradiation mainly resulted in chain scission and induction of oxygenated groups and radicals as well as unsaturation. The thermal behavior of the irradiated PTFE and the fate of the radicals were studied comprehensively. Apart from fluorine, saturated and unsaturation fluorocarbons and oxygen-containing groups were released during heating. Furthermore, irradiation-generated peroxy radicals were transformed into alkyl radicals in a partly reversible process. A proposal for the complex reaction mechanisms of irradiation PTFE was improved by annealing.