A method of microwave treatment of wood with a moisture content (based on dry weight) of at least 12% for rapid drying and stress relief which includes determining an area of the wood that is not to be treated, selectively subjecting a surface of the wood outside said determined area to microwave radiation at a frequency (f) in the range of from about 0.1 to about 24 GHz to provide a modified wood zone having increased permeability relative to the untreated wood, wherein said zone is located in an exterior shell of the wood and has wooden rays directed from the core of the wood to the irradiated surface.