Patent ID: 8049188

Claim:
A method of cleaning a first surface region at least partly covered with contaminant or undesirable material, said contaminant or undesirable material being removable or convertible by exposure to atomic hydrogen, wherein the method includes: providing one or several second surface regions with catalytic material ( 11 ) in proximity to the first surface region, said catalytic material ( 11 ) being selected to cause dissociation of molecular hydrogen and said one or several second surface regions having a total surface area which is at least twice a surface area of said first surface region, directing a gas flow of a molecular hydrogen containing gas ( 8 ) or gas mixture to or along said one or several second surface regions in such a manner that said molecular hydrogen containing gas ( 8 ) or gas mixture gets in contact with said one or several second surface regions before passing said first surface region, wherein part of the molecular hydrogen dissociates to atomic hydrogen which is transported with said gas flow to the first surface region removing or converting said contaminant or undesirable material.