A thermoplastic resin has excellent heat resistance and thermal stability, low water absorption properties, excellent surface hardness and mechanical strength. A thermoplastic resin includes a constituent unit (a) that is derived from a (meth)acrylate monomer and represented by the formula (1); a constituent unit (b) that is derived from a vinyl monomer and represented by the formula (2); and a constituent unit (c) that is derived from a vinyl monomer and represented by the formula (3), and the weight percentage of the constituent unit (a), based on the total weight of the all constituent units, is 60 to 85% by weight, the weight percentage of the constituent unit (b), based on the total weight of the all constituent units, is 5 to 30% by weight, and the weight percentage of the constituent unit (c), based on the total weight of the all constituent units, is 5 to 15% by weight.