A gear-change device for changing gears in a gearbox, with - a first group of gear-change elements (23, 27, 28, 29) and - a second group of gear-change elements (13, 45, 46), - a gearshift shaft which is arranged to be displaceable along a longitudinal axis and rotatable about the longitudinal axis, wherein at least one gear-change element (23, 27, 28, 29) of the first group and at least one gear-change element (13, 45, 46) of the second group can be selected by displacing the gearshift shaft into one of a plurality of possible displacement positions and the selected gear-change elements can be actuated by turning the gearshift shaft, wherein the at least one selected gear-change element of the first group can be actuated in phase or with an overlapping or offset phase shift in relation to the at least one selected gear-change element of the second group, wherein - the gearshift shaft has a first master element, associated with the first group of gear-change elements (23, 27, 28, 29), and a second master element, associated with the second group of gear-change elements (13, 45, 46), wherein the two master elements (69, 70) are rotationally coupled with the gearshift shaft or are connected fixedly to the gearshift shaft, characterised in that - a plurality of second slave elements (73a - 73e) are associated with the second group of gear-change elements (13, 45, 46), with each of the second slave elements (73a - 73e) being coupled with at least one gear-change element (13, 45, 46) of the second group, and the second master element, dependent on the sliding position of the gearshift shaft, cooperating with one of the second slave elements (73 - 73e) in such a way that a rotary motion of the gearshift shaft and of the second master element coupled therewith is transmitted to that slave element of the second slave elements (73a - 73e) which is associated with the respective sliding position, and from this slave element to the at least one gear-change element (13, 45, 46) of the second group which is coupled therewith, and - the master elements (69, 70) and the slave elements (72a - 72h, 73a - 73e) are matched to each other such that upon turning of the gearshift shaft, starting from a state in which all the gear-change elements (23, 27, 28, 29, 13, 45, 46) are opened, for all possible gear-change operations always first a gear-change element (23, 27, 28, 29) of the first group begins to close and only after the closing of a gear-change element (23, 27, 28, 29) of the first group has begun does a gear-change element (13, 45, 46) of the second group begin to close. - a first group of gear-change elements (23, 27, 28, 29) and - a second group of gear-change elements (13, 45, 46), - a gearshift shaft which is arranged to be displaceable along a longitudinal axis and rotatable about the longitudinal axis, wherein at least one gear-change element (23, 27, 28, 29) of the first group and at least one gear-change element (13, 45, 46) of the second group can be selected by displacing the gearshift shaft into one of a plurality of possible displacement positions and the selected gear-change elements can be actuated by turning the gearshift shaft, wherein the at least one selected gear-change element of the first group can be actuated in phase or with an overlapping or offset phase shift in relation to the at least one selected gear-change element of the second group, wherein - the gearshift shaft has a first master element, associated with the first group of gear-change elements (23, 27, 28, 29), and a second master element, associated with the second group of gear-change elements (13, 45, 46), wherein the two master elements (69, 70) are rotationally coupled with the gearshift shaft or are connected fixedly to the gearshift shaft, - a plurality of second slave elements (73a - 73e) are associated with the second group of gear-change elements (13, 45, 46), with each of the second slave elements (73a - 73e) being coupled with at least one gear-change element (13, 45, 46) of the second group, and the second master element, dependent on the sliding position of the gearshift shaft, cooperating with one of the second slave elements (73 - 73e) in such a way that a rotary motion of the gearshift shaft and of the second master element coupled therewith is transmitted to that slave element of the second slave elements (73a - 73e) which is associated with the respective sliding position, and from this slave element to the at least one gear-change element (13, 45, 46) of the second group which is coupled therewith, and - the master elements (69, 70) and the slave elements (72a - 72h, 73a - 73e) are matched to each other such that upon turning of the gearshift shaft, starting from a state in which all the gear-change elements (23, 27, 28, 29, 13, 45, 46) are opened, for all possible gear-change operations always first a gear-change element (23, 27, 28, 29) of the first group begins to close and only after the closing of a gear-change element (23, 27, 28, 29) of the first group has begun does a gear-change element (13, 45, 46) of the second group begin to close.