The invention relates to an apparatus for selectively shrinking a film, which is wrapped around a product (P), comprising a frame (9), a driven conveyor (1) mounted on said frame (9) and intended to transport sequentially a plurality of products (P), a heat source (5) arranged under the conveyor (1) and which generates a hot fluid, and a plurality of nozzles (5.1) oriented towards the low part of said conveyor (1), the hot fluid being provided to said nozzles (5.1). The heat source (5) and the nozzles (5.1) are fixed and the apparatus also comprises closing means by means of which the hot fluid reaches only the front and rear ends of each product (P).