Abstract: A film stretching machine with tentering hook chain tracks extending through several consecutive processing zones is constructed of preassembled standardized exchangeable structural groups permitting a modular type of construction. These structural groups include venting cells of the same kind which are fully pre-equipped and are arranged along the left and right edges of the film web to be stretched. Exchangeable blower boxes with nozzle fingers or arms having a standardized width are installable between opposite venting cells of a processing zone. The dimensions of the venting cells are matched to the dimensions of typical shipping containers in order to achieve efficient packaging possibilities. The length of the venting cells advantageously corresponds to two or three times a standard spacing of adjustment spindles used for adjusting the spacing of the tentering hook chain tracks. The width of the standardized blower boxes may vary stepwise by twice the width of the venting cells.