Aliphatic polyester composition, molded product, and manufacturing method of aliphatic polyester

A method of continuously manufacturing an aliphatic polyester composition, comprising a step of supplying a cyclic ester, molecular weight adjusting agent, and polymerization catalyst to an extruder and then polymerizing in the extruder;

• wherein
• the temperature in the extruder is gradually increased in two or more stages from a raw material supply port to a discharge port,
• the temperature at the discharge port is a temperature where the melt viscosity of the composition at the discharge port is from 100 to 2000 Pa·s,
• the free acid concentration in the cyclic ester is 10 eq/t or less, and
• the unreacted cyclic ester concentration in the aliphatic polyester composition is less than 2 wt. %.