A machine for sealing containers using a film, comprising: - a supporting framework; - a first jaw member comprising a plurality of seats for respective containers to be sealed; - a second jaw member facing towards the seats of the first jaw member, the first jaw member and the second jaw member being movable one relative to the other between a first condition, in which the two jaw members (21, 22) are separated from each other by an interspace suitable for receiving a film, and a second condition, in which the two jaw members (21, 22) are clamped together and, in use, press the film against the containers in the seats; - a film feeding device; - a positioning apparatus capable of positioning the film in the interspace between the first jaw member and the second jaw member; - a sealing system which is associated with the first jaw member or with the second jaw member and is capable of sealing the film on the containers in the seats when the two jaw members (21, 22) are in the second condition, obtaining sealed containers; and - a film cutting system; the seats of said plurality being side by side one after another along a longitudinal line extending between a first side and a second side of the interspace; the positioning apparatus comprising a first gripping device and a second gripping device, that is movable between a first position close to the film feeding device and a second position close to the first gripping device; the second gripping device in the first position being capable of gripping one edge of the film which projects from the film feeding device; the second gripping device being capable of pulling the gripped film with a movement towards the second position, thereby positioning the film in the interspace at said plurality of seats; the first gripping device being capable of gripping the edge of the positioned film, when the second gripping device is in the second position, the second gripping device being capable of releasing the film and returning to the first position; characterised in that the film feeding device faces towards the first side of the interspace; the film cutting system is capable of cutting the film at least along a cutting line positioned between the film feeding device and the seat closest to the first side of the interspace; and the first gripping device is positioned at the second side of the interspace and the second gripping device is movable parallel to the longitudinal line between the first position and the second position. - a supporting framework; - a first jaw member comprising a plurality of seats for respective containers to be sealed; - a second jaw member facing towards the seats of the first jaw member, the first jaw member and the second jaw member being movable one relative to the other between a first condition, in which the two jaw members (21, 22) are separated from each other by an interspace suitable for receiving a film, and a second condition, in which the two jaw members (21, 22) are clamped together and, in use, press the film against the containers in the seats; - a film feeding device; - a positioning apparatus capable of positioning the film in the interspace between the first jaw member and the second jaw member; - a sealing system which is associated with the first jaw member or with the second jaw member and is capable of sealing the film on the containers in the seats when the two jaw members (21, 22) are in the second condition, obtaining sealed containers; and - a film cutting system;