To provide a cooling method of a glass substrate wherein a heating quantity of a heater required for adjusting the temperature distribution of the substrate is reduced when cooling the glass substrate after being heated at a maximum temperature.

This cooling method uses a continuous heat treatment furnace having a plurality of heating chambers partitioned in the carrying direction of a heat treatment object, and a carrying means for carrying the heat treatment object to the adjacent heating chamber, and anneals the glass substrate after being heated at the maximum temperature while successively carrying the glass substrate to the continuous heating chambers set so that an inside temperature gradually becomes low for advancing in the carrying direction. Direct cooling by blowing of outside air introduced into the heating chambers 5 and/or indirect cooling by a cooling pipe is performed on a central part of the glass substrate 1 carried in the heating chamber 5 and/or a setter 3 being a substrate carrying material and/or a part close to the adjacent higher inside temperature other heating chamber.