To provide a method for preventing crevice corrosion which is capable of easily preventing the occurrence of corrosion with simple work in a crevice between members of even a structure in the seawater or the like and is excellent in maintenance.

When butt welding or the like is executed by butting a chill plate 3 to a base metal 11, an air film 7 is formed in a part 6 coated with a coating agent capable of holding the air film when submerged in the water even under an environment immersed with a corrosive liquid 5 and a corroding liquid does not infiltrate this part and, therefor, the corrosion does not occur in the crevice spacing between the members even of the structure wetted with the seawater or the like. In addition, there is no need for a sacrificial electrode which is heretofore necessary for instance, the welded structure in the sea and the repair work in the environment where the crevice corrosion is liable to occur is drastically reduced.