Sewing machine for bags comprising a strip sewn according to a helical and/or spiral trajectory, comprising: - a shelf with a free end; - a platform that is disposed at the free end of said shelf; - an arm that is overlapped and disposed side-by-side to said shelf; said arm being provided with a free end; - a sewing unit that is disposed at the free end of said arm; said sewing unit comprising at least one needle and at least one foot (P1, P2); said at least one needle making upward and downward travels along a vertical trajectory; - an operating sewing station that is disposed in said platform; said operating station being provided with a sewing line that passes through said vertical trajectory covered by said at least one needle and directed along a basically perpendicular direction with respect to said shelf; - a first reel that is disposed at the free end of said arm in correspondence of the sewing unit; - a second reel that is disposed at the free end of said shelf in correspondence of said operating station; - a stop edge in order to guide the strip in the operating station; - support means that support the stop edge and are fixed above the shelf; - adjustment means (1 a) for said stop edge; said stop edge being adapted to be in idle position, wherein said stop edge is remote with respect to said operating station, and in working position, wherein said stop edge is proximal to said operating station; said support means being adapted to move said stop edge between said idle position and said operating position; said adjustment means being adapted to adjust the distance between said at least one needle and said stop edge when said stop edge is in operating position. - a shelf with a free end; - a platform that is disposed at the free end of said shelf; - an arm that is overlapped and disposed side-by-side to said shelf; said arm being provided with a free end; - a sewing unit that is disposed at the free end of said arm; said sewing unit comprising at least one needle and at least one foot (P1, P2); said at least one needle making upward and downward travels along a vertical trajectory; - an operating sewing station that is disposed in said platform; said operating station being provided with a sewing line that passes through said vertical trajectory covered by said at least one needle and directed along a basically perpendicular direction with respect to said shelf; - a first reel that is disposed at the free end of said arm in correspondence of the sewing unit; - a second reel that is disposed at the free end of said shelf in correspondence of said operating station; - a stop edge in order to guide the strip in the operating station; - support means that support the stop edge and are fixed above the shelf; - adjustment means (1 a) for said stop edge; said stop edge being adapted to be in idle position, wherein said stop edge is remote with respect to said operating station, and in working position, wherein said stop edge is proximal to said operating station; said support means being adapted to move said stop edge between said idle position and said operating position; said adjustment means being adapted to adjust the distance between said at least one needle and said stop edge when said stop edge is in operating position.