摘要:
Pasty solution 5 made by dissolving membrane-forming polymer 2 and plasticizer 3 in water 4 is applied to wall surface 1 in the form of liquid film 6. The plasticizer 3 improves flexibility and elongation of membrane formable by the membrane-forming polymer. Dirt substance 8 on the wall surface 1 is caused to adhere to the liquid film 6. Water 4 of the liquid film 6 is allowed to evaporate gradually so as to turn the liquid film 6 into flexible membrane 7 which is peelable intact. After dried, the flexible membrane 7 is peeled off intact from the wall surface 1 while carrying the dirt substance 8 adhering thereto.