The invention provides a patterned
phase difference plate and a manufacturing method thereof. The patterned
phase difference plate which is large in area and excellent in long-distance dimensional stability of a
phase difference region is manufactured through a relatively simple method. The patterned phase difference plate is manufactured by a method including a step of applying a
liquid crystal aligning agent to form a
coating film, a step of exposing the
coating film through a
photomask to form a photo-alignment film, and a step of applying polymerizable
liquid crystal on the photo-alignment film and hardening the polymerizable
liquid crystal to form a liquid
crystal layer. The liquid
crystal aligning agent contains a
polymer having a cinnamate structure, an
azobenzene structure or a main chain
decomposition type structure. The glass substrate is provided with an alignment mark part serving as an alignment index for the glass substrate on a
substrate surface on which the liquid
crystal aligning agent is coated. In the scanning
exposure, the relative position of the
photomask with respect to the alignment mark portion is detected, and the
coating film is irradiated with
radiation while the relative position of the
photomask with respect to the glass substrate is corrected on the basis of the detection result.