Device for manufacturing cushions filled with a medium from synthetic pre-processed tubular foil (2). Flexible pre-processed tubular foil is supplied to the device by a supply device in a supply direction. The pre-processed tubular foil is supplied in flat condition. The pre-processed tubular foil has a first (6) and a second (7) longitudinal edge opposite each other. An introduction means (9) for introducing a medium is provided. A cutting means (8) is present for making a cut in the pre-processed tubular foil only and at least near the first longitudinal edge of the foil. Sealings means (11) are provided for sealing the pre-processed tubular foil parallel and between the introduction means and the second longitudinal edge, for sealing off the cut. Series of cushions or a cushion filled with a medium according to the invention have a second closed off longitudinal edge, a first cut-through longitudinal edge formed by two ends situated opposite it, and a longitudinal seal situated between the first and the second longitudinal edge.