A method of producing a liquid crystal cell includes: a thin-film forming step of forming, on a surface of one electrode-attached substrates including a TFT substrate and a slot substrate, the TFT substrate including a first dielectric substrate, TFTs, and patch electrodes electrically connected to the TFTs, the slot substrate including a second dielectric substrate and a slot electrode supported on the second dielectric substrate and having slots, a thin film so as to cover the patch electrodes and/or the slot electrode; and a light irradiating step of irradiating the thin film with light including p-polarized light to provide the thin film with alignment-regulating capability of aligning liquid crystal molecules to thereby obtain an alignment film. The thin film includes a polymer including a photoreactive functional group and exhibiting the alignment-regulating capability of the thin film in a direction orthogonal to a polarization axis of the p-polarized light.