Provided is a dew condensation prevention device for a discharge chute. A tip end portion of the discharge chute has inverted truncated cone-shaped internal and external chutes, a space is provided between an outer surface of the internal chute and an inner surface of the external chute, and a first air discharge port that communicates with the space is provided between respective lower ends of the two chutes. A cylindrical portion having an air reservoir in the interior thereof is provided to surround an outer peripheral surface of the external chute, and by providing an opening between an inner peripheral edge of a lower surface of the cylindrical portion and the outer peripheral surface of the external chute, a second air discharge port that communicates with the air reservoir is provided. Air input pipes for introduction of dry air are connected to the external chute and the cylindrical portion, respectively.