Polyester-based resin composition, method for producing same, and molding using resin composition

A polyester-based resin composition comprising:

• a resin component which contains 80 to 98 mass % of polyester resin (A) including aromatic dicarboxylic acid units and diol units, and 20 to 2 mass % of polyamide resin (B) including diamine units and dicarboxylic acid units, the diamine units containing 70 mol % or more m-xylylenediamine units and the dicarboxylic acid units containing 70 mol % or more α,ω-aliphatic dicarboxylic acid units;
• and
• 0.005 to 0.1 parts by mass of epoxy-functional polymer (C) which contains styrene units represented by formula (c1) and glycidyl (meth)acrylate units represented by formula (c2), with respect to 100 parts by mass of the resin component:
• where R1 to R4 each independently represent a hydrogen atom or an alkyl group having carbon atoms of 1 to 12.