Treatment device for treating food products with conditioned air, comprising a housing which delimits a treatment space and is provided with an entry and an exit, which are in communication with one another via the treatment space, at least one conveying means for conveying the products from the entry throughout the treatment space to the exit, the conveying means between the entry and the exit following a conveying path with several windings which are situated one above the other, the conveying means comprising at least one driven hollow drum with rotary shaft, air-conditioning means for conditioning the air, air-circulation means for circulating conditioned air throughout the treatment space via the hollow drum, the air-circulation means, viewed in the direction of flow of the conditioned air towards the conveying path, being arranged downstream of the air-conditioning means.