The invention relates to a strain relief device (40) for glass fiber cables (50) having a cable jacket (56) and at least one glass fiber (57) and fibers (58) arranged between the at least one glass fiber (57) and the cable jacket (56), in which, at one end of the glass fiber cable (54), the cable jacket (56) is cut back, in order to provide strain relief at a distance from a termination or connection of the at least one glass fiber (57) from which the cable jacket (56) has been removed, said strain relief means comprising a main body (1) with a clamping body (3) and a securing body (21) with a further clamping body (22), wherein the main body (1) and the securing body (21) can be connected to one another so that at least some of the fibers (58) which are exposed when the cable jacket (56) is cut back from the at least one glass fiber (57) are secured adjacent to their exit from the cable jacket (56) between the clamping body (3) and the further clamping body (22) by a clamping means. In addition, the invention relates to a method for attaching such a strain relief device.