PURPOSE: To efficiently remove mold and prevent other growth and invasion of mold, by removing at least the surface layer of a mold-bearing plane to be painted by high pressure water, then applying a moldcide agent on the mold- free surface, and finishing-coating with an antimoulding agent-contg. painting material.

CONSTITUTION: A 2nd coating (2B) bearing mold 3 is removed with water at ≥500kg/cm2 high pressure, mold 3 in the interface of 1st and 2nd coatings (2A) and (2B) is removed, and the exposed surface of the 1st coaring (2A) is cleaned. Then, after a moldcide agent (e.g. alcohols) is applied on the surface, another coating is formed using an anti-molding agent-contg. paint 5 so as to prevent other growth and invasion of mold.