A liquid crystal display device having a liquid crystal layer formed by irradiating and curing with ultraviolet rays a liquid crystal composition containing a liquid crystal and a polymerizable compound disposed between a pair of substrates provided with electrodes, and at least one of the substrates being provided with a liquid crystal alignment film to vertically align a liquid crystal, wherein said liquid crystal composition contains a compound represented by the following formula, and said liquid crystal alignment film is obtained from a liquid crystal alignment treating agent containing a polymer having a side chain structure represented by the following formula or formula, and a side chain structure represented by the following formula: wherein X 1 is at least one selected from the group consisting of the following formula [1-a] to formula [1-g], X 2 is at least one bond 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-, X 3 is a single bond or -(CH 2) a - (a is an integer of from 1 to 15), X 4 is at least one bond group selected from the group consisting of a single bond, -O-, -OCH 2 -, -COO- and -OCO-, X 5 is a benzene ring, a cyclohexane ring or a C 17-51 divalent organic group having a steroid skeleton, wherein any optional hydrogen atom on the benzene ring or the cyclohexane ring may be substituted by a C 1-3 alkyl group, a C 1-3 alkoxy group, a C 1-3 fluorinated alkyl group, a C 1-3 fluorinated alkoxy group or a fluorine atom, X 6 is at least one bond group selected from the group consisting of a single bond, -O-, -OCH 2 -, -CH 2 O-, - COO- and -OCO-, X 7 is a benzene ring or a cyclohexane ring, wherein any 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 fluorinated alkyl group, a C 1-3 fluorinated alkoxy group or a fluorine atom, p is an integer of from 0 to 4, and X 8 is at least one selected from the group consisting of a C 1-18 alkyl group, a C 1-18 fluorinated alkyl group, a C 1-18 alkoxy group and a C 1-18 fluorinated alkoxy group, wherein X A is a hydrogen atom or a benzene ring, X B is at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and X C is at least one selected from the group consisting of a C 1-18 alkyl group, a C 1-18 fluorinated alkyl group, a C 1-18 alkoxy group and a C 1-18 fluorinated alkoxy group, wherein Y 1 and Y 3 are each independently at least one bond group selected from the group consisting of a single bond, -(CH 2) a - (a is an integer of from 1 to 15), -O-, -CH 2 O-, -COO- and -OCO-, Y 2 is a single bond or -(CH 2) b - (b is an integer of from 1 to 15), Y 4 and Y 5 are each independently at least one divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, or a C 17-51 divalent organic group having a steroid skeleton, wherein any optional hydrogen atom on the cyclic group may be substituted by a C 1-3 alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy group, or a fluorine atom, n is an integer of from 0 to 4, and Y 6 is a C 1-18 alkyl, fluorinated alkyl, alkoxy or fluorinated alkoxy group, -Y 7 -Y 8 wherein Y 7 is at least one bond 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 Y 8 is a C 8-22 alkyl group or a C 6-18 fluorinated alkyl group, -W 1 -W 2 -W 3 -W 4 wherein W 1 and W 3 are each independently at least one bond 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-, W 2 is a single bond, 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 cyclohexane ring and a heterocyclic ring, wherein any optional hydrogen atom on the cyclic group may be substituted by a C 1-3 alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy group, and W 4 is at least one structure selected from the group consisting of the following formula [3-a] to formula [3-g]: wherein W A is a hydrogen atom or a benzene ring, W B is at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic group, and W C is a C 1-18 alkyl, fluorinated alkyl, alkoxy or fluorinated alkoxy group, wherein the liquid crystal alignment treating agent is a liquid crystal alignment treating agent containing a polyimide precursor obtainable by a reaction of a tetracarboxylic acid component and a diamine component containing a diamine having a side chain structure of the above formula or formula and a diamine having a side chain structure represented by the above formula, or a polyimide obtainable by imidizing the polyimide precursor, and wherein the diamine having a side chain structure represented by the above formula or formula is a diamine represented by the following formula: wherein Y is a structure represented by the above formula or formula, and m is an integer of from 1 to 4, and wherein the diamine having a side chain structure represented by the above formula is a diamine represented by the following formula: wherein W is a structure represented by the above formula, and q is an integer of from 1 to 4.