PURPOSE: To press-form a metal film for use as shaping, by press-fitting a metal film to a separable vessel, decompressing the two chambers separated by the metal film, and opening the rear piece chamber.

CONSTITUTION: A vacuum vessel 1 is separated by drawing back a frame 3 by means of a moving means 4. A metal film 12 is put to cover the top of a frame 2, and the frame 3 is moved forward to press-fit the frames 2, 3 through the metal film 12, thereby dividing the vessel 1 into chambers 1', 1". Then, mainpulating a valve 14, the chambers 1', 1" are decompressed to 10 millibars or less, and a valve 16 is opened to the atmosphere. Then, due to pressure difference between the chambers 1' and 1", the metal film 12 if press-formed on a die for shaping 6. Next, by valve manipulation, the communication between the vacuum source 13 and atmosphere 15 is cut off, and the frame 3 is drawn back, and a crosslinkable high molecular substance is laminated on the formed metal film 12 by a known method to react and set. Then, the metal film 12 which has been pressed from the back is separated from the die for shaping 6, and taken out.