The invention relates to a film stretching plant comprising a furnace (3) consisting of a plurality of treatment zones (1, 1a) each comprising a ventilation unit (2). The film (4) can be supplied to the furnace (3) via a film inlet region (5) and can be thermally treated by zone in the treatment zones (1, 1a). The treatment fluid (6) supplied to the film stretching plant flows over the film (4) in the treatment zones (1, 1a), on the upper side and lower side thereof. For the film stretching plant according to the invention, the treatment fluid (6) can be circulated in the respective treatment zone (1, 1a) through the respective ventilation unit (2) assigned thereto for thermal treatment of the film (4), and a portion (6a) of the treatment fluid (6) is guided from the respective treatment zone (1) to the subsequent treatment zone (1a) of the technical process. Said portion (6a) of the treatment fluid (6) guided into the subsequent treatment zone (1a) is guided in a manner decoupled from the passage region of the film (4) in the treatment zones (1, 1a), wherein each treatment zone (1, 1a) is equipped with a heat exchanger, by means of which the portion (6a) of the treatment fluid (6) supplied thereto can be adjusted to the required temperature for thermal treatment of the film (4) in said treatment zone of the technical process.