Graphene can be used to avoid the oxidation of metallic films. This work explores the effectiveness of such stabilizing effect on Cobalt (Co) films intercalated between Graphene and Ir(111). After intercalation at 300 degrees C, two Co films are exposed to ambient pressure and investigated using Co-K edge X-ray Absorption Near Edge Spectroscopy. The formation of a disordered oxide phase is observed, and associated to the presence of some non-intercalated Co. Further annealing at 500 degrees C causes the oxide reduction to metallic Co which further intercalates below the Graphene. Once the intercalation is completed, Graphene prevents the Co from oxidation under ambient pressure conditions. (C) 2018 Elsevier B.V. All rights reserved.