An alignment film or a phase difference device with small shift from a desired alignment direction and a display unit including the same are provided. The alignment film includes: a substrate having a plurality of grooves extending in a specific direction on a surface; and a non-alignment thin film formed along a surface of the plurality of grooves. The phase difference device includes: an alignment film that has a substrate having a plurality of grooves extending in a specific direction on a surface and a non-alignment thin film formed along a surface of the plurality of grooves; and a phase difference layer that is provided being contacted with a surface of the non-alignment thin film, and includes a liquid crystal material that is aligned along an extending direction of a dent formed by the non-alignment thin film and is polymerized.