A treatment device for treating food products with conditioned air comprises a housing which delimits a treatment space and is provided with an entry and an exit, at least one conveying device for conveying the products from the entry throughout the treatment space to the exit, the conveying device between the entry and the exit following a conveying path with several windings which are situated one above the other, air-circulation device for circulating conditioned air throughout the treatment space via a hollow drum. According to a first aspect, air-conditioning device are provided upstream of the air-circulation device for conditioning the air. According to a second aspect, at least one winding of the conveying path near the entry has a pitch which is different to the pitch of the downstream windings.