A liquid crystal composition that has negative dielectric anisotropy, and contains a compound represented by formula as a first component: wherein, in formula, R 1 is alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine; R 2 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons or alkenyloxy having 2 to 12 carbons; ring A and ring C are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine; ring B is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z 1 and Z 2 are independently a single bond, -CH 2 CH 2 -, -CH 2 O-, -OCH 2 -, - COO- or -OCO-; and a is 1, 2 or 3, b is 0 or 1, and a sum of a and b is 3 or less, and at least one polar compound having a polymerizable group selected from the group of compounds represented by formula as a first additive: wherein, in formula, R 11 is hydrogen, fluorine, chlorine or alkyl having 1 to 25 carbons, and in the alkyl, at least one piece of -CH 2 - may be replaced by -NR 0 -, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- or cycloalkylene having 3 to 8 carbons, and at least one tertiary carbon (>CH-) may be replaced by nitrogen (>N-), and in the groups, at least one hydrogen may be replaced by fluorine or chlorine, in which R 0 is hydrogen or alkyl having 1 to 12 carbons; R 12 is a polar group having at least one of an oxygen atom having an OH structure, a sulfur atom having an SH structure and a nitrogen atom having a primary, secondary or tertiary amine structure; ring L, ring M and ring N are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and in the rings, at least one hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine; Z 7 and Z 8 are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one piece of -CH 2 - may be replaced by -O-, -CO-, -COO- or -OCO-, and at least one piece of -CH 2 CH 2 - may be replaced by -CH=CH-, - C(CH 3)=CH-, -CH=C(CH 3)- or -C(CH 3)=C(CH 3)-, and in the groups, at least one hydrogen may be replaced by fluorine or chlorine; P 1, P 2 and P 3 are a polymerizable group; Sp 1, Sp 2 and Sp 3 are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one piece of - CH 2 - may be replaced by -O-, -COO-, -OCO- or -OCOO-, and at least one piece of -CH 2 CH 2 - may be replaced by -CH=CH- or -C≡C-, and in the groups, at least one hydrogen may be replaced by fluorine, chlorine, -OCO-CH=CH 2 or -OCO-C(CH 3)=CH 2; g and h are independently 0, 1, 2, 3 or 4, and a sum of g and h is 0, 1, 2, 3 or 4; j and o are independently 0, 1, 2, 3 or 4; and k is 1, 2, 3 or 4.