A resin composition comprising: a polymer whose enthalpy of fusion observed within a temperature range of 10°C or higher and lower than 60°C in differential scanning calorimetry is 30 J/g or more; a thermally conductive material whose thermal conductivity is 1 W/(m·K) or higher, and a polymer whose melting peak temperature or glass transition temperature observed in differential scanning calorimetry is 50°C or higher and 180°C or lower, provided that the polymer is different from the polymer, wherein a content of the polymer is 30 wt% or more and 99 wt% or less and a content of the polymer is 1 wt% or more and 70 wt% or less, with respect to 100 wt% of the total amount of the polymer and the polymer, a content of the thermally conductive material is 5 parts by weight or more and 80 parts by weight or less, with respect to 100 parts by weight of the total amount of polymer components contained in the resin composition, wherein the polymer is a polymer comprising a constitutional unit derived from ethylene and a constitutional unit represented by the following formula, and the polymer is a crosslinked polymer, wherein at least a part of molecules of the polymer are linked together via intermolecular covalent bonding; wherein R represents a hydrogen atom or a methyl group; L 1 represents -CO-O-, -O-CO-, or -O-; L 2 represents a single bond, -CH 2 -, -CH 2 -CH 2 -, -CH 2 -CH 2 -CH 2 -, -CH 2 -CH -CH 2 -, or -CH 2 -CH(CH 2 OH)-; L 3 represents a single bond, -CO-O-, -O-CO-, -O-, -CO-NH-, -NH-CO-, -CO-NH-CO-, - NH-CO-NH-, -NH-, or -N(CH 3)-; L 6 represents an alkyl group having 14 or more and 30 or less carbon atoms; and a left side and a right side of each of the horizontal chemical formulas for describing chemical structures of L 1, L 2, and L 3 correspond to an upper side of the formula and a lower side of the formula, respectively, and wherein the enthalpy of fusion of the polymer, the melting peak temperature or glass transition temperature of the polymer, and the thermal conductivity of the thermally conductive material are measured according to the description. a polymer whose enthalpy of fusion observed within a temperature range of 10°C or higher and lower than 60°C in differential scanning calorimetry is 30 J/g or more; a thermally conductive material whose thermal conductivity is 1 W/(m·K) or higher, and a polymer whose melting peak temperature or glass transition temperature observed in differential scanning calorimetry is 50°C or higher and 180°C or lower, provided that the polymer is different from the polymer, wherein a content of the polymer is 30 wt% or more and 99 wt% or less and a content of the polymer is 1 wt% or more and 70 wt% or less, with respect to 100 wt% of the total amount of the polymer and the polymer, a content of the thermally conductive material is 5 parts by weight or more and 80 parts by weight or less, with respect to 100 parts by weight of the total amount of polymer components contained in the resin composition, wherein the polymer is a polymer comprising a constitutional unit derived from ethylene and a constitutional unit represented by the following formula, and the polymer is a crosslinked polymer, wherein at least a part of molecules of the polymer are linked together via intermolecular covalent bonding; wherein R represents a hydrogen atom or a methyl group; L 1 represents -CO-O-, -O-CO-, or -O-; L 2 represents a single bond, -CH 2 -, -CH 2 -CH 2 -, -CH 2 -CH 2 -CH 2 -, -CH 2 -CH -CH 2 -, or -CH 2 -CH(CH 2 OH)-; L 3 represents a single bond, -CO-O-, -O-CO-, -O-, -CO-NH-, -NH-CO-, -CO-NH-CO-, - NH-CO-NH-, -NH-, or -N(CH 3)-; L 6 represents an alkyl group having 14 or more and 30 or less carbon atoms; and a left side and a right side of each of the horizontal chemical formulas for describing chemical structures of L 1, L 2, and L 3 correspond to an upper side of the formula and a lower side of the formula, respectively, and wherein the enthalpy of fusion of the polymer, the melting peak temperature or glass transition temperature of the polymer, and the thermal conductivity of the thermally conductive material are measured according to the description. R represents a hydrogen atom or a methyl group; L 1 represents -CO-O-, -O-CO-, or -O-; L 2 represents a single bond, -CH 2 -, -CH 2 -CH 2 -, -CH 2 -CH 2 -CH 2 -, -CH 2 -CH -CH 2 -, or -CH 2 -CH(CH 2 OH)-; L 3 represents a single bond, -CO-O-, -O-CO-, -O-, -CO-NH-, -NH-CO-, -CO-NH-CO-, - NH-CO-NH-, -NH-, or -N(CH 3)-; L 6 represents an alkyl group having 14 or more and 30 or less carbon atoms; and a left side and a right side of each of the horizontal chemical formulas for describing chemical structures of L 1, L 2, and L 3 correspond to an upper side of the formula and a lower side of the formula, respectively, and wherein the enthalpy of fusion of the polymer, the melting peak temperature or glass transition temperature of the polymer, and the thermal conductivity of the thermally conductive material are measured according to the description.