The invention relates to a device for filling a container of a collapsible type with a product. The device comprising a valve housing with a filling tube, which is insertable into a filling duct of the container to supply the product to the compartment through a product path; a piston element arranged in the product path and comprising a valve body and an end element, the piston element being movable between a first position, in which the valve body blocks the product path and the end element counteract dripping, and a second position, in which the valve body opens the product path and the end element defines, together with the outlet portion, a filling passage; and a squeezing apparatus establishes a seal between the filling tube and the filling duct.