A method of manufacturing a photoalignment layer includes: applying a photoalignment agent including a copolymer of at least one of cyclobutanedianhydride and a cyclobutanedianhydride derivative, and diamine, and a crosslinking agent including an alkylene group having a formula —CnH2n—, wherein n is a natural number, on a substrate; pre-baking the photoalignment agent applied on the substrate to form a pre-baked photoalignment agent; hard-baking the pre-baked photoalignment agent to form a hard-baked photoalignment agent; irradiating the hard-baked photoalignment agent with a light source thereby photoaligning the photoalignment agent; and secondarily baking the photoalignment agent irradiated with the light source, where in the application of the photoalignment agent on the substrate, the photoalignment agent applied on an edge portion of the substrate is applied in about 30 to about 70 wt %, relative to the photoalignment agent applied on the center portion of the substrate.