To reduce production cost by enabling the use of a thin electroformed panel.

A plurality of gooves 23, 23,... having appropriate width are provided to the bottom part of the recessed part 22 of a male mold main body 21 in parallel to the short sides of the recessed part 22 at a predetermined pitch. The exhaust passage 24 extended from the short side of the male mold main body 21 is opened to the male mold main body 21 so as to cross the grooves 23, 23,... at a right angle and the parts of the grooves 23, 23,... crossing the exhaust passage 24 are allowed to communicate with the exhaust passage 24. An electroformed panel 5 having a required uneven pattern formed to the surface thereof is fitted in the recessed part 22 so that the rear surface of the electroformed panel 5 is opposed to a male mold 2 to discharge air from the exhaust passage 24. By this constitution, the exhaust passage 24 and the grooves 23, 23,... are evacuated to fix the electroformed panel to the recessed part 22.