A liquid crystal panel included in a scanning antenna includes: a TFT substrate including a first dielectric substrate, a TFT supported by the first dielectric substrate, a gate bus line, a source bus line, a patch electrode, and a first alignment film covering the patch electrode; a slot substrate including a second dielectric substrate, a slot electrode formed on a first main surface of the second dielectric substrate and including a slot disposed corresponding to the patch electrode, and a second alignment film covering the slot electrode; and a liquid crystal layer provided between the TFT substrate and the slot substrate and containing a liquid crystal molecule including an isothiocyanate group. The first alignment film and the second alignment film are each independently formed of a polyimide-based alignment film material. In each of the first alignment film and the second alignment film, a density of a carboxyl group on a film surface in contact with the liquid crystal layer is less than a density of a carboxyl group inside a film.