A laminated body comprising: a substrate layer; and a gas barrier layer provided on at least one surface of the substrate layer and formed of a gas barrier film formed of a cured product of a coating material for a gas barrier, wherein the coating material for a gas barrier comprises: a polycarboxylic acid; a polyamine compound; a polyvalent metal compound; and a base, wherein (molar number of -COO- groups included in the polycarboxylic acid)/(molar number of amino groups included in the polyamine compound)=100/20 to 100/90, the polycarboxylic acid is a homopolymer or a copolymer of α,β-unsaturated carboxylic acid, the polyamine compound is a polymer which has two or more aminos in the main chain, a side chain, or a terminal, (a chemical equivalent of -COO- groups included in the polycarboxylic acid)/(a chemical equivalent of polyvalent metal contained in the polyvalent metal compound)=100/0.1 to 100/80, the polyamine compound includes polyethylene imine, the base includes one or more of volatile base selected from a group consisting of ammonia, morpholine, alkylamine, 2-dimethyl amino ethanol, N-methyl morpholine, ethylene diamine, and tertiary amines, an aqueous solution thereof or a mixture thereof, and the metal in the polyvalent metal compound belongs to group 2 to 13 of the periodic table. a substrate layer; and a gas barrier layer provided on at least one surface of the substrate layer and formed of a gas barrier film formed of a cured product of a coating material for a gas barrier, wherein the coating material for a gas barrier comprises: a polycarboxylic acid; a polyamine compound; a polyvalent metal compound; and a base, wherein (molar number of -COO- groups included in the polycarboxylic acid)/(molar number of amino groups included in the polyamine compound)=100/20 to 100/90, the polycarboxylic acid is a homopolymer or a copolymer of α,β-unsaturated carboxylic acid, the polyamine compound is a polymer which has two or more aminos in the main chain, a side chain, or a terminal, (a chemical equivalent of -COO- groups included in the polycarboxylic acid)/(a chemical equivalent of polyvalent metal contained in the polyvalent metal compound)=100/0.1 to 100/80, the polyamine compound includes polyethylene imine, the base includes one or more of volatile base selected from a group consisting of ammonia, morpholine, alkylamine, 2-dimethyl amino ethanol, N-methyl morpholine, ethylene diamine, and tertiary amines, an aqueous solution thereof or a mixture thereof, and the metal in the polyvalent metal compound belongs to group 2 to 13 of the periodic table. a polycarboxylic acid; a polyamine compound; a polyvalent metal compound; and a base, wherein (molar number of -COO- groups included in the polycarboxylic acid)/(molar number of amino groups included in the polyamine compound)=100/20 to 100/90, the polycarboxylic acid is a homopolymer or a copolymer of α,β-unsaturated carboxylic acid, the polyamine compound is a polymer which has two or more aminos in the main chain, a side chain, or a terminal, (a chemical equivalent of -COO- groups included in the polycarboxylic acid)/(a chemical equivalent of polyvalent metal contained in the polyvalent metal compound)=100/0.1 to 100/80, the polyamine compound includes polyethylene imine, the base includes one or more of volatile base selected from a group consisting of ammonia, morpholine, alkylamine, 2-dimethyl amino ethanol, N-methyl morpholine, ethylene diamine, and tertiary amines, an aqueous solution thereof or a mixture thereof, and the metal in the polyvalent metal compound belongs to group 2 to 13 of the periodic table.