Abstract: A liquid crystal display device having a liquid crystal layer made of a cured product formed by irradiating a liquid crystal composition disposed between a pair of substrates provided with electrodes with ultraviolet light from an ultraviolet irradiation apparatus and at least one of the substrates being provided with a liquid crystal alignment film to vertically align liquid crystal, where the liquid crystal composition contains a curable resin, a bifunctional monomer, a compound of the following formula [1-1a], a compound of the following formula [2-1a] and a monomer having at least one polar group selected from a hydroxy group, a carboxy group and a phosphoric acid group, where the liquid crystal alignment film is obtainable from a liquid crystal alignment treating agent containing a polymer having a side chain structure of the following formula [4-1a] or formula [4-2a]