Noble interactions between Ar and carbons are observed for carbons, such as carbon nanotubes and carbon blacks by means of mass-analyzed thermal desorption. The absorption states exist at around 300 K as well as at around 100 K. X-ray photoelectron spectroscopy reveals that Ar2p shows the chemical shifts. These results suggest that Ar is in charge and it is in valence state, or gives the evidence of the chemical interaction.