To provide a production method of a polyester sheet that is improved so that IV reduction may be suppressed to the minimum, and haze increase of a polyester sheet may be suppressed.

The production method of a polyester sheet is provided in which polyester is melt-extruded into a sheet-like shape on a casting drum surface. The production method of a polyester sheet is characterized in that a vent-type twin screw extruder in which an inner diameter (diameter) D of a cylinder is 140 mm or more is used as an extruder, melt extrusion is performed under the condition that an extrusion output Q (kg/hr) per unit time and the number of revolutions N (rpm) of a screw satisfy the following expression (1), a casting drum having a diameter d of 1,500 mm or more is used, and a molten sheet is cooled and cured under the condition that the number of revolutions n (rpm) and a diameter d (mm) of a casting drum satisfy the following expression (2). 5.2×10^-6×D^2.8≤Q/N≤15.8×10^-6×D^2.8 ... (1), 750≤d/n≤4000 ... (2).