Yongdusa Temple, built during the reign of Koryo King Kwangjong in 962, was also the site where an iron banner pole was located. Because the pole was situated outdoors, the combination of moisture from the air and oxygen did cause some corrosion, but the additional factor of environmental pollution considerably speeded up this process. Therefore the most important fact in conserving metal treasures located outdoors is to block the object's exposure to elements in the air causing the corrosion. The banner pole was conserved in the following way. First a condition analysis was conducted of the surface of the pole. After that the pollutants and dust were cleaned off and the old filling material and coatings removed. A water repellency agentt was used to protect the object from moisture and in cracks a 1:1 mixture of araldite HV 427 and SV 427 was mixed with paint and applied. To protect the surface, HAC-5 wax, which is used to protect outdoor sculptures, was applied in order to reduce to a minimal amount the damage caused by noxious substances permeating the surface of outdoor metal national treasures.