A method for producing a hot-dip galvanized steel sheet using a continuous hot-dip galvanizing apparatus that includes: a vertical annealing furnace in which a heating zone, a soaking zone, and a cooling zone are arranged in this order; and a hot-dip galvanizing line located downstream of the cooling zone, the method comprising: subjecting a steel sheet to annealing by conveying the steel sheet through the heating zone, the soaking zone, and the cooling zone in the stated order in the annealing furnace, in which the steel sheet is conveyed in an upward direction to form one pass and in a downward direction to form another pass along a steel sheet conveyance path respectively in the heating zone, the soaking zone, and the cooling zone while passing through at least one upper hearth roll provided in an upper portion of each of the heating zone, the soaking zone, and the cooling zone and at least one lower hearth roll provided in a lower portion of each of the heating zone, the soaking zone, and the cooling zone; and applying a hot-dip galvanized coating on the steel sheet discharged from the cooling zone, using the hot-dip galvanizing line, wherein humidified gas is supplied to the soaking zone in a manner such that: in the pass in which the steel sheet moves upward, the humidified gas is supplied from a first humidified gas supply port provided at a position that is higher by 1.0 m or more and 5.0 m or less than the center of the lower hearth roll and that overlaps the steel sheet in the pass when viewed from the side of the soaking zone; and in the pass in which the steel sheet moves downward, the humidified gas is supplied from a second humidified gas supply port provided at a position that is lower by 1.0 m or more and 5.0 m or less than the center of the upper hearth roll and that overlaps the steel sheet in the pass when viewed from the side of the soaking zone. subjecting a steel sheet to annealing by conveying the steel sheet through the heating zone, the soaking zone, and the cooling zone in the stated order in the annealing furnace, in which the steel sheet is conveyed in an upward direction to form one pass and in a downward direction to form another pass along a steel sheet conveyance path respectively in the heating zone, the soaking zone, and the cooling zone while passing through at least one upper hearth roll provided in an upper portion of each of the heating zone, the soaking zone, and the cooling zone and at least one lower hearth roll provided in a lower portion of each of the heating zone, the soaking zone, and the cooling zone; and applying a hot-dip galvanized coating on the steel sheet discharged from the cooling zone, using the hot-dip galvanizing line, wherein humidified gas is supplied to the soaking zone in a manner such that: in the pass in which the steel sheet moves upward, the humidified gas is supplied from a first humidified gas supply port provided at a position that is higher by 1.0 m or more and 5.0 m or less than the center of the lower hearth roll and that overlaps the steel sheet in the pass when viewed from the side of the soaking zone; and in the pass in which the steel sheet moves downward, the humidified gas is supplied from a second humidified gas supply port provided at a position that is lower by 1.0 m or more and 5.0 m or less than the center of the upper hearth roll and that overlaps the steel sheet in the pass when viewed from the side of the soaking zone. in the pass in which the steel sheet moves upward, the humidified gas is supplied from a first humidified gas supply port provided at a position that is higher by 1.0 m or more and 5.0 m or less than the center of the lower hearth roll and that overlaps the steel sheet in the pass when viewed from the side of the soaking zone; and in the pass in which the steel sheet moves downward, the humidified gas is supplied from a second humidified gas supply port provided at a position that is lower by 1.0 m or more and 5.0 m or less than the center of the upper hearth roll and that overlaps the steel sheet in the pass when viewed from the side of the soaking zone.