To provide a light guide plate, a metal mold for the light guide plate, and a manufacturing method for the metal mold for the light guide plate which doesn't make large differences in the thickness of the light guide plate with positions and improve the yields of manufacturing processes even when it is manufactured on mass-production.

The light guide plate 140 has a slanting part 144 for guiding incident light and has a end part 141 in the incidence side of the incident light, an end part 142 opposite the incidence side, and an intermediate part 143 which is formed between those incidence-side end part and opposite-side end part and has the slanting part so that the thickness of the intermediate part is larger than the thicknesses of the incidence-side end part and the opposite-side end part.