To manufacture a sheet-like laminated body of high quality used for a liquid crystal display element by a process more simplified than ever before at low cost.

The manufacturing method comprises a lamination process in which diffusion sheets 12 and 18 of which planar size is larger than the size of the product are placed over the surface of the front and/or back side of at least one of the lens sheets of which planar size is larger than the size of the product and in which convex lenses formed in the uniaxial direction are disposed adjacently almost all over, a cutting process for cutting the periphery of the laminated body of the diffusion sheet and the lens sheet to the size of the product, and a joining process for joining the lens sheet and the diffusion sheet at least one or more positions of the periphery.