A method of producing an adhesive sheet comprising an adhesive composition layer, the method comprising: applying a composition comprising a polythiol compound, a (meth)acrylic compound, a radical generator, a Michael addition catalyst, and a surface conditioner to a support to form a coating film; and polymerizing through a Michael addition reaction, the polythiol compound and the (meth)acrylic compound in the coating film to make the coating film an adhesive composition layer, wherein the polythiol compound is selected from the group consisting of: a polythiol in which a portion other than the thiol groups is an aliphatic hydrocarbon; a polythiol obtainable by replacing halogen atoms of a halohydrin adduct of an alcohol with thiol groups; a polythiol that is a hydrogen sulfide reaction product of a polyepoxide compound; a thioglycolic acid ester obtainable by an ester-forming reaction between a polyhydric alcohol having from 2 to 6 hydroxyl groups in a molecule thereof and thioglycolic acid; a mercapto fatty acid ester obtainable by an ester-forming reaction between a polyhydric alcohol having from 2 to 6 hydroxyl groups in a molecule thereof and a mercapto fatty acid; a thiol isocyanurate compound obtainable by a reaction between an isocyanurate compound and a thiol; a thiol that includes a polysulfide group; a silicone modified with thiol groups; and silsesquioxane modified with thiol groups; the (meth)acrylic compound has a plurality of at least one of an acryloyl group or a methacryloyl group, and has a ring structure; the radical generator is a thermal radical generator consisting of a peroxide; the Michael addition catalyst is an amine-based catalyst; the surface conditioner is a silicone acrylate-based surface conditioner, and a ratio (Ac/SH) of a total molar number (Ac) of the at least one of an acryloyl group or a methacryloyl group contained in the (meth)acrylic compound to a total molar number of thiol groups contained in the polythiol compound before polymerization is from 0.25 to 0.80, and wherein a total content of components to is 80% by mass or more with respect to a total mass of the composition for an adhesive composition layer. applying a composition comprising a polythiol compound, a (meth)acrylic compound, a radical generator, a Michael addition catalyst, and a surface conditioner to a support to form a coating film; and polymerizing through a Michael addition reaction, the polythiol compound and the (meth)acrylic compound in the coating film to make the coating film an adhesive composition layer, wherein the polythiol compound is selected from the group consisting of: a polythiol in which a portion other than the thiol groups is an aliphatic hydrocarbon; a polythiol obtainable by replacing halogen atoms of a halohydrin adduct of an alcohol with thiol groups; a polythiol that is a hydrogen sulfide reaction product of a polyepoxide compound; a thioglycolic acid ester obtainable by an ester-forming reaction between a polyhydric alcohol having from 2 to 6 hydroxyl groups in a molecule thereof and thioglycolic acid; a mercapto fatty acid ester obtainable by an ester-forming reaction between a polyhydric alcohol having from 2 to 6 hydroxyl groups in a molecule thereof and a mercapto fatty acid; a thiol isocyanurate compound obtainable by a reaction between an isocyanurate compound and a thiol; a thiol that includes a polysulfide group; a silicone modified with thiol groups; and silsesquioxane modified with thiol groups; the (meth)acrylic compound has a plurality of at least one of an acryloyl group or a methacryloyl group, and has a ring structure; the radical generator is a thermal radical generator consisting of a peroxide; the Michael addition catalyst is an amine-based catalyst; the surface conditioner is a silicone acrylate-based surface conditioner, and a ratio (Ac/SH) of a total molar number (Ac) of the at least one of an acryloyl group or a methacryloyl group contained in the (meth)acrylic compound to a total molar number of thiol groups contained in the polythiol compound before polymerization is from 0.25 to 0.80, and wherein a total content of components to is 80% by mass or more with respect to a total mass of the composition for an adhesive composition layer.