1 b and the third optical plate 1 c is layered on top these optical plates 1 a 1 b 1 c are then subjected to bonding and laminating by capturing so as to leave gaps g 1 g 2 inside a mold 8 which can be assembled and disassembled being made up of four pushing plates having walls frame walls which move in four directions and having on an inside bottom face thereof a protuberance 7 of square or circular section serving as a holding section for the mold 8 the planar shape may be c shape with the frame wall on one side being movable next the three optical plates 1 a 1 b 1 c layered inside the mold 8 are pressed from the upper surface with a predetermined pressure that is the optical plates 1 a 1 b 1 c are pressed between both principal planes s and s u2032 so that the adhesive 6 overflows out to the side faces surrounding the optical plates 1 a 1 b 1 c in this case the gaps g 1 and g 2 between the mold 8 and the optical plates are filled with adhesive 6 such that the adhesive.