To provide a mold manufacturing method capable of easily corresponding even to the production of a lens substrate having a size of every kind at a low cost, a mold formed thereby, the lens substrate manufactured using the mold, a transmission type screen and a rear type projector.

In the manufacturing method of the mold used for forming the lens substrate, the mold is obtained by combining a plurality of unit substrates having a shape corresponding to the surface shape of the lens substrate on its surface and a predetermined size. Each of the unit substrates is constituted of a metal material and a plurality of the unit substrates are spread all over the base substrate to be joined to the base substrate through a joining layer. The joining layer is mainly constituted of a metal material having a low melting point and surface roughing treatment is applied to the vicinity of the region where the unit substrates come into contact with each other on the surface of the base substrate.