NOVELTY - The transesterification device comprises a frame (100) accommodating functional modules for transesterification process, a reactor and a smelter (200) for heating the animal fats, and a settling tank to treat the unmelted fats from the smelter. The resulting mixture in the settling tank is re-injected in the smelter. The smelter comprises a filter in its outlet for performing filtration of the resulting mixture by gravity. The reactor comprises a vent and a valve. The reactive supply is automated, and provided to the reactor depending on the temperature of the content of the reactor.    USE - The device is useful for transesterification of animal fats for the production of biodiesel.    ADVANTAGE - The device is versatile and compact, and ensures economical, easy and rapid transesterification of animal fats without any external constraints and with safe transesterification reaction, good melting of fats and good settling of melted fats.    DETAILED DESCRIPTION - The transesterification device comprises a frame (100) accommodating functional modules for transesterification process, a reactor and a smelter (200) for heating the animal fats, and a settling tank to treat the unmelted fats from the smelter. The resulting mixture in the settling tank is re-injected in the smelter. The smelter comprises a filter in its outlet for performing filtration of the resulting mixture by gravity. The reactor comprises a vent and a valve. The reactive supply is automated, and provided to the reactor depending on the temperature of the content of the reactor. The reactor is equipped with an overflow device. The mixture inside the reactor is produced by a movement in a closed circuit and a movement in a pump assuring the supply of melted fat in the reactor. A second reactor is used for performing pre-esterification reaction of acid for optimal operation of esterification.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic side view of a device for transesterification of animal fats.    Frame (100)    Plate (110)    Roller unit (111)    Smelter (200)    Smelting tank (210)    Mixing unit. (220)