In one embodiment, a method of manufacturing an original plate includes forming a first film on a first substrate, wherein an etching rate of the first film by a chemical solution including hydrofluoric acid is larger than an etching rate of the first substrate by the chemical solution. The method further includes forming a second film on the first film, wherein an etching rate of the second film by the chemical solution is smaller than the etching rate of the first film by the chemical solution. The method further includes etching the first substrate by the chemical solution using the first film and the second film as masks to form, on the first substrate, a first region having a first height, a second region having a second height different from the first height, and a first slope located between the first region and the second region.