Abstract: This granulating device (1) comprises a drum (2) mounted so as to rotate around a substantially horizontal axis. On its inner periphery, this drum (2) carries lifters (20) intended to entrain and lift granules of a substance which is crystallized over a part of its path and it is associated with an entry channel (7) for fine granules which opens into the vicinity of a first end, which is away from that at which the granules are discharged from the drum. A spraying bar (5) is provided inside the latter for spraying the product to be granulated. According to the invention, a fluidized bed device (3) is arranged inside the drum for cooling the granules which are stirred and lifted in the drum, as they become coated by spraying. This device enables the granules to grow uniformly and to cool and dry efficiently, resulting in the production of granules of a very good quality and controlled particle size.