A thermoplastic resin, comprising: an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer, or an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer and a matrix resin comprising one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein the total content of the alkyl acrylate is 20 to 50 % by weight, and the alkyl acrylate coverage value as calculated by Equation 1 below is 65 or more: X = G − Y / Y × 100, wherein G represents the total gel content (%) of the thermoplastic resin, and Y represents the content (% by weight) of the alkyl acrylate in the gel of the thermoplastic resin, wherein the total gel content and the content (% by weight) of the alkyl acrylate ion the gel of the thermoplastic resin are measured as disclosed in the specification, wherein, based on 100 % by weight in total of the copolymer, the copolymer comprises 25 to 50 % by weight of alkyl acrylate rubber (a-1) having a DLS average particle diameter of 50 to 120 nm or a TEM average particle diameter of 32.5 to 84 nm and 50 to 75 % by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer (b-1), wherein the copolymer has a grafting degree of 60 to 150 %, and the copolymer (b-1) has a weight average molecular weight of 40,000 to 120,000 g/mol, wherein the grafting degree and the weight average molecular weight are measured as disclosed in the specification, and wherein DLS average particle diameter is measured by dynamic light scattering and TEM average particle diameter is measured by transmission electron microscope, as disclosed in the specification. an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer, or an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer and a matrix resin comprising one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein the total content of the alkyl acrylate is 20 to 50 % by weight, and the alkyl acrylate coverage value as calculated by Equation 1 below is 65 or more: X = G − Y / Y × 100, wherein G represents the total gel content (%) of the thermoplastic resin, and Y represents the content (% by weight) of the alkyl acrylate in the gel of the thermoplastic resin, wherein the total gel content and the content (% by weight) of the alkyl acrylate ion the gel of the thermoplastic resin are measured as disclosed in the specification, wherein, based on 100 % by weight in total of the copolymer, the copolymer comprises 25 to 50 % by weight of alkyl acrylate rubber (a-1) having a DLS average particle diameter of 50 to 120 nm or a TEM average particle diameter of 32.5 to 84 nm and 50 to 75 % by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer (b-1), wherein the copolymer has a grafting degree of 60 to 150 %, and the copolymer (b-1) has a weight average molecular weight of 40,000 to 120,000 g/mol, wherein the grafting degree and the weight average molecular weight are measured as disclosed in the specification, and wherein DLS average particle diameter is measured by dynamic light scattering and TEM average particle diameter is measured by transmission electron microscope, as disclosed in the specification.