A drying device for a coating machine equipped with a rotary pan (1), in which the products to be coated are introduced, includes air injecting means (5) for supplying air to dry the products inside the rotary pan (1), and an exhaust air pipe (7), equipped with perforated hollow head pieces which can be removed, adapted to be immersed in a heap of products to be coated. The pipe (7) is supported by sliding means (21) which are moved in a direction longitudinal to the same pipe between a working position, in which the exhaust pipe (7) is operated, and an advanced position, so as to allow maintenance operation on the exhaust pipe (7) performed from outside through the front opening (3a) of the pan (1).