A PROCESSED LUMBER MATERIAL CONTAINING A COMPOUND OF THE FORMULA: WHEREIN A IS 6-CHLORO-3-PYRIDYL, 2-CHLORO-5-THIAZOLYL, TETRAHYDROFURAN-3-YL OR THE LIKE R1 IS HYDROGEN, METHYL, ETHYL OR THE LIKE R2 IS METHYL, METHYLAMINO OR THE LIKE R3 IS METHYL OR THE LIKE X IS NITROGEN OR CH Y IS CYANO, NITRO OR TRIFLUOROACETYL Z IS NH OR SULFUR D IS OXYGEN OR -N(CH3)- M IS 0 OR 1 AND N IS 2 OR 3, HAS EXCELLENT INSECT-PROOFNESS.