PURPOSE: To improve the production efficiency and working accuracy by providing guide holes through a guide film composed of a flexible film and adhesive compound and sticking a plurality of flexible wiring boards formed to block-like shapes to the guide film by aligning the guides of the wiring boards to the guide holes, and then, working the wiring boards while the boards are supported on the guide film.

CONSTITUTION: A guide film 1 is constituted of a flexible film 11 having a rigidity and adhesive compound 12 for fixing flexible wiring boards while the wiring boards are supported on the film 11. Then guide holes 14 are bored at desired positions of the film 1 by means of a guide hole boring means 102. After forming the holes 14, a plurality of flexible wiring boards formed to block-like shapes are stuck to the film 1 by aligning the common guides of the wiring boards to the holes 14. Then the outside shape of each wiring board is worked by means of an outside shape working means 201 on the basis of the guides of the wiring boards. After working, each wiring board is subjected to continuity tests with a continuity test jig 41 while the wiring boards are supported on the film 1.