A liquid crystal display device, which is in a transparent state when no voltage is applied and in a scattering state when a voltage is applied, and which comprises a liquid crystal layer formed by disposing a liquid crystal composition containing a polymerizable compound which undergoes a polymerization reaction by ultraviolet rays, between a pair of substrates provided with an electrode, and irradiating the liquid crystal composition with ultraviolet rays and curing it in such a state that the liquid crystal composition partly or entirely shows liquid crystallinity, and at least one of the substrates being provided with a liquid crystal alignment film to vertically align a liquid crystal, wherein the liquid crystal alignment film is a liquid crystal alignment film obtained from a liquid crystal aligning agent containing a solvent and a polymer having a side chain structure (first side chain structure) represented by the following formula or and a side chain structure (second side chain structure) represented by the following formula: wherein X 1 and X 3 are each independently at least one binding group selected from the group consisting of a single bond, - (CH 2) a - (wherein a is an integer of from 1 to 15), -O-, -CH 2 O-, -COO- and -OCO-; X 2 is a single bond or -(CH 2) b - (wherein b is an integer of from 1 to 15); X 4 is at least one bivalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, or a C 17-51 bivalent organic group having a steroid skeleton, provided that an optional hydrogen atom on the cyclic group may be substituted by a C 1-3 alkyl group, a C 1-3 alkoxy group, a C 1-3 fluorine-containing alkyl group, a C 1-3 fluorine-containing alkoxy group or a fluorine atom; X 5 is at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, provided that an optional hydrogen atom on such a cyclic group may be substituted by a C 1-3 alkyl group, a C 1-3 alkoxy group, a C 1-3 fluorine-containing alkyl group, a C 1-3 fluorine-containing alkoxy group or a fluorine atom; n is an integer of from 0 to 4; and X 6 is at least one member selected from the group consisting of a C 1-18 alkyl group, a C 1-18 fluorine-containing alkyl group, a C 1-18 alkoxy group and a C 1-18 fluorine-containing alkoxy group; -x 7 -x 8 wherein X 7 is at least one binding group selected from the group consisting of a single bond, -O-, -CH 2 O-, -CONH-, -NHCO-, -CON(CH 3)-, -N(CH 3)CO-, -COO- and -OCO-; and X 8 is a C 8-22 alkyl group or a C 6-18 fluorine-containing alkyl group; -Y 1 -Y 2 -Y 3 -Y 4 wherein Y 1 and Y 3 are each independently at least one binding group selected from the group consisting of a single bond, -O-, -NH-, -N(CH 3)-, -CH 2 O-, -CONH-, -NHCO-, -CON(CH 3)-, -N(CH 3)CO-, -COO- and -OCO-; Y 2 is a C 1-18 alkylene group, or a C 6-24 organic group having at least one cyclic group selected from the group consisting of a benzene ring, a cyclocyclohexane ring and a heterocyclic ring, provided that an optional hydrogen atom on such a cyclic group may be substituted by a C 1-3 alkyl group, a C 1-3 alkoxy group, a C 1-3 fluorine-containing alkyl group, a C 1-3 fluorine-containing alkoxy group or a fluorine atom; and Y 4 is at least one member selected from the group consisting of structures represented by the following formulae [2-a] to [2-g]: wherein Y a is a hydrogen atom or a benzene ring; Y b is a single bond, or at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring; and Y c is at least one member selected from the group consisting of a C 1-18 alkyl group, a C 1-18 fluorine-containing alkyl group, a C 1-18 alkoxy group and a C 1-18 fluorine-containing alkoxy group, wherein the liquid crystal aligning agent is a liquid crystal aligning agent containing a polyimide precursor obtained by a reaction of a diamine component containing a diamine having the side chain structure represented by the above formula or and a diamine having the side chain structure represented by the above formula, and a tetracarboxylic acid component, or a polyimide obtained by imidizing the polyimide precursor, wherein the liquid crystal aligning agent contains at least one generator selected from the group consisting of a photo-radical generator, a photo-acid generator and a photo-base generator, wherein the liquid crystal aligning agent contains a compound having at least one member selected from the group consisting of structures represented by the following formulae [b-1] to [b-8]: wherein B 1 is a hydrogen atom or a benzene ring, B 2 is at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and B 3 is at least one member selected from the group consisting of a C 1-8 alkyl group, a C 1-18 fluorine-containing alkyl group, a C 1-18 alkoxy group and a C 1-18 fluorine-containing alkoxy group, and wherein the liquid crystal aligning agent contains a compound having at least one group selected from the group consisting of an epoxy group, an isocyanate group, an oxetane group, a cyclocarbonate group, a hydroxy group, a hydroxyalkyl group and a lower alkoxyalkyl group.