In a method for treating wood, a wood treatment device for a long-term treatment of wood is provided. An active agent for wood treatment is applied to a carrier material and the carrier material provided with the active agent for wood treatment is introduced into the receiving space of a hollow cylindrical body of the wood treatment device. The wood treatment device is driven into the wood. A thrust pin of the wood treatment device is displaced to release a first outlet opening at an open end face of the hollow cylindrical body and a second outlet opening in a wall surface of the hollow cylindrical body of the wood treatment device to bring into contact the receiving space with the wood and to release the active agent for wood treatment into the wood. The wood treatment device is left behind in the wood.