A photo-alignment material, a liquid crystal display device using the photo-alignment material, and a manufacturing method. The photo-alignment material is a polymer having a photo-reactive ethenyl group on a main chain. When used as a photo-alignment layer, the photo-alignment material enables improved alignment stability against external shocks, light, and heat. The liquid crystal display device includes a first substrate, a second substrate, a liquid crystal layer formed between the first and second substrates, and a photo-alignment layer formed at least on the first substrate, with the photo-alignment layer formed from a photo-alignment material having an ethenyl group at a main chain.