METHACRYLIC RESIN COMPOSITION AND MOLDED BODY

Provided are a methacrylic resin composition that has adequate optical properties for practical use and excellent heat resistance, thermal stability, external appearance, and shaping processability, and a shaped product containing the same. The methacrylic resin composition comprises a methacrylic resin, the methacrylic resin comprising: 50 mass% to 97 mass% of a methacrylic acid ester monomer unit (A); 3 mass% to 30 mass% of a structural unit (B) having a cyclic structure-containing main chain; and 0 mass% to 20 mass% of another vinyl monomer unit (C) that is copolymerizable with a methacrylic acid ester monomer, wherein the methacrylic resin satisfies a specific condition; and the methacrylic resin composition has a weight average molecular weight residual ratio of 80% or more upon heating under a nitrogen atmosphere at 280°C for 1 hour, and has a weight average molecular weight residual ratio of 80% or more upon heating in air at 280°C for 0.5 hours.