PURPOSE: To work quickly a hole to a thin metallic sheet without wasting a special viscous and plastic medium by placing said medium on the thin metallic sheet placed on a die and compressing impulsively the sheet by using a compressing plate.

CONSTITUTION: A thin metallic sheet 4 is placed on a die 5 and a viscous and plastic medium 2 is installed concentrically with the die hole via a positioning plate 4. A compressing plate 1 is lowered to compress impulsively the medium 2 in a semi-hermetic state at a speed of ≥0.1m/S. Stress is thus concentrated near the die hole and a hole of the same shape as the shape of the die hole is pierced to the sheet 4. A plastic single or composite material which has a positive viscosity at the service temp. and retrains ≥45% permanent set after 50% compressive strain is applied thereto and consists essentially of a high polymer or metal is used for said medium 2. Since no punch is used in this method, the method is effective in working a hole to a glass plate, etc.