The method for producing a glass sheet by down-drawing includes an air pressure controlling step of controlling the air pressure of a furnace outside space formed between a furnace and a covering part that covers the furnace, the furnace including a forming furnace and a lehr, a melting step of melting glass raw materials to form molten glass, a supplying step of supplying the molten glass to a forming cell disposed inside the forming furnace, a forming step of forming a glass sheet by allowing the molten glass to flow down the forming cell, an annealing step of cooling the glass sheet while allowing the glass sheet to flow in one direction in the lehr, and a cutting step of cutting the glass sheet that has been cooled. In the air pressure controlling step, air pressure is controlled such that the air pressure is higher, inside the furnace outside space, at a position more toward the upstream side of the flow direction of the glass sheet.