In situ XANES (x‐ray absorption near‐edge structure) was used to study galvanostatic reduction of the passive film on iron. In a borate buffer, the film appears to be removed in a layer‐by‐layer fashion by reductive dissolution during the first potential arrest. A burst of dissolution takes place at the end of the arrest for slow reduction rates. During the course of reduction, the remaining film shows a composition change from ferric oxide toward . This may indicate that the film has an inner layer of . Galvanostatic reduction of the passive film grown on iron in leads to complete reduction of the passive film to ferrous oxide or hydroxide without any detectable dissolution.