Roller shutter working both as roll-up shutter and jalousie, comprising - a plurality of slats arranged adjacent to one another and arranged for sheltering from wind, sun, light and bad weather; - at least a driving chain crosswise to which the plurality of slats is fastened; and wherein: - the driving chain comprises a plurality of driving chain links and a plurality of connecting chain links articulated together so as to form a succession so that at least some of the driving chain links are articulated with and individually interposed between two connecting chain links (9, 9A, 9 B) and a plurality of connecting chain links ( 9, 9 A, 9 B) is articulated and interposed between two driving chain links; - at least some of the driving chain links are fixed, link by link, to at least a respective slat and are arranged to drive it in order to reversibly open and close a plurality of openings, each of which is interposed between two adjacent slats; - both the driving chain links and the connecting chain links extend along less than the half of the total width (W 1) of the roller shutter; characterized in that - a plurality of driving chain links is singularly fastened to at least one slat through a first ( 13 A) and a second ( 13 B) hinging pin that, by rotating together with the respective driving chain link, drive the respective slat; - at least some driving chain links are articulated, link by link, with a first and adjacent connecting chain link ( 9 A) through its first hinging pin ( 13 A) and is articulated with a second and adjacent connecting chain link ( 9 B) through its second hinging pin ( 13 B); - each slat forms a first and a second longitudinal edge; - at least some slats are fastened to the respective first ( 13 A) and second ( 13 B) hinging pin; - each slat in proximity of its first longitudinal edge, and the second longitudinal edge of each slat is arranged for resting onto an adjacent slat when the opening between the two slats is closed. - a plurality of slats arranged adjacent to one another and arranged for sheltering from wind, sun, light and bad weather; - at least a driving chain crosswise to which the plurality of slats is fastened; - the driving chain comprises a plurality of driving chain links and a plurality of connecting chain links articulated together so as to form a succession so that at least some of the driving chain links are articulated with and individually interposed between two connecting chain links (9, 9A, 9 B) and a plurality of connecting chain links ( 9, 9 A, 9 B) is articulated and interposed between two driving chain links; - at least some of the driving chain links are fixed, link by link, to at least a respective slat and are arranged to drive it in order to reversibly open and close a plurality of openings, each of which is interposed between two adjacent slats; - both the driving chain links and the connecting chain links extend along less than the half of the total width (W 1) of the roller shutter; characterized in that - a plurality of driving chain links is singularly fastened to at least one slat through a first ( 13 A) and a second ( 13 B) hinging pin that, by rotating together with the respective driving chain link, drive the respective slat; - at least some driving chain links are articulated, link by link, with a first and adjacent connecting chain link ( 9 A) through its first hinging pin ( 13 A) and is articulated with a second and adjacent connecting chain link ( 9 B) through its second hinging pin ( 13 B); - each slat forms a first and a second longitudinal edge; - at least some slats are fastened to the respective first ( 13 A) and second ( 13 B) hinging pin; - each slat in proximity of its first longitudinal edge, and the second longitudinal edge of each slat is arranged for resting onto an adjacent slat when the opening between the two slats is closed.