To provide a process for producing a polyester resin having a hydroxy group and a carboxy group at terminals and used for a powder coating material at good efficiency.

In a process for producing a polyester resin comprising an acid component based on an aromatic dicarboxylic acid and an alcohol component based on an aliphatic glycol and having a limiting viscosity of 0.15-0.40, a hydroxy value of 20-50 mgKOH, and an acid value of 5-40 mgKOH/g, a polyester (P) having a limiting viscosity of at least 0.20 is depolymerized with an at least dihydric alcohol component (A) and water in an amount of 0.01-0.2 mol per mol of the acid component constituting the polyester P.