The release of ions and excited neutrals by the interaction of low energy electrons with CO on (100) W is studied by a time-of-flight technique. The flight time distributions, approximate threshold energies, adsorption kinetics, and dependence behavior of the desorbed particle currents upon heating and heavy electron bombardment are presented for the excited neutrals,CO+andO+ions in the temperature range 110–600 K. The fact that the binding state producing the excited neutrals is identical with the state releasingCO+ions suggests that the excited neutrals are CO molecules.