The invention relates to a device for continuously carrying out chemical reactions. The device comprises a microwave generator, a microwave applicator accommodating a microwave-transparent tube, and an isothermal reaction section which is arranged such that the material to be reacted is guided inside the microwave-transparent tube through a microwave applicator which is used as the heating zone and in which it is heated to reaction temperature by means of microwaves that are emitted from the microwave generator into the microwave applicator. The material to be reacted, which is heated and optionally under pressure, is transferred from the microwave applicator to an isothermal reaction zone once it has left the heating zone, said reaction zone being arranged downstream of the heating zone, and is cooled once it has left the isothermal reaction zone.