NOVELTY - The device (1) comprises a reactor (2) that comprises a reactor interior space (3) for receiving a biomass charge, a catalyst unit (4) arranged outside of the reactor interior space, and a cooling device (5). The catalyst unit comprises three catalyst stages, which are disposed behind the other in a flow direction of the generated gases. Each of a first catalyst-stage and last catalyst-stage is provided with a separately actuable heating device. The reactor is provided with a heating device comprising heating stages, and comprises a cover imageable with a heat resistant, renewable sealing.    USE - The device is useful for producing a biofuel such as bio-petroleum.    ADVANTAGE - The device is capable of efficiently, rapidly and economically producing the biofuel with high production yield and quality.    DETAILED DESCRIPTION - The device (1) comprises a reactor (2) that comprises a reactor interior space (3) for receiving a biomass charge, a catalyst unit (4) arranged outside of the reactor interior space, and a cooling device (5). The catalyst unit comprises three catalyst stages, which are disposed behind the other in a flow direction of the generated gases. Each of a first catalyst-stage and last catalyst-stage is provided with a separately actuable heating device. The reactor is provided with a heating device comprising heating stages, and comprises a cover imageable with a heat resistant, renewable sealing. A pipe mill is arranged in the reactor interior space. The cover comprises an opening (13) by which the reactor interior space stands with the catalyst unit in the flow direction. The cooling device connected with the catalyst unit opens into a collecting container, and is provided with a cooled upstanding safety pipe. The reactor and the catalyst unit are provided with a thermal insulation.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a device for producing a biofuel.    Device (1)    Reactor (2)    Reactor interior space (3)    Catalyst unit (4)    Cooling device (5)    Opening. (13)