PURPOSE: To obtain a board with a protective film excellent in workability and stripping properties which is useful for production of a thin polyimide film based flexible printed circuit board.

CONSTITUTION: A copper film is applied through a heat resistant adhesive on one side of a polyimide film having the other side applied separably with a protective plastic film through adhesive thus producing a flexible printed circuit board. Alternatively, a protective plastic film applied with a separable tackifier, the tackiness thereof being lowered through irradiation with ultraviolet rays, is laminated on a film applied on one side thereof with a copper toil by 60μm thick or less thus producing a flexible printed wiring board.