The present invention relates to a preservative for preserving wood comprising 5-methyl-2-trifluoromethylfuran-3-carboxylic acid anilide derivative represented by the following formula,wherein R represents an iropropyl group or an isopropoxy group as an active ingredient. The preservative for preserving wood has an excellent preservative effect on various wood-decay fungi at an extremely low dose, is economically efficient, and imposes a small burden on the environment. The present invention also relates to a method for treating wood using the preservative.
