Fall protection device (10, 11, 12) having an assembly base, having a securing element connected to the assembly base, and a connector device which is attached to the securing element and enables mechanical coupling to an external securing means, in particular a rope or a hook, wherein - the assembly base is embodied so as to be telescopic and adjustable for length; and - the assembly base by way of one end is able to be fastened, in particular screwed, to and/or on a rafter of a roof, and by way of another end is able to be fastened, in particular screwed, to and/or on an adjacent rafter of the roof; - the securing element by means of holding means is releasably fastened to the telescopic assembly base; - the holding means have a clamping element and a mating clamping element, the two latter (100, 110) being able to be connected to one another in such a manner that the clamping element and the mating clamping element jam a portion of the assembly base, wherein the clamping element and the mating clamping element are connected by means of at least one screw connection which by tightly screwing the clamping element and the mating clamping element to one another enables the assembly base to be jammed therebetween; - the connector device that permits mechanical coupling to the external securing means comprises an eyelet or is formed by an eyelet which is attached indirectly or directly to that end of the securing element that is distal from the assembly base; and - the other end of the securing element, thus the end of the securing element that is proximal to the assembly base, is fastened to the clamping element, characterized in that - the mating clamping element is formed by a component that is U-shaped in cross section. - the assembly base is embodied so as to be telescopic and adjustable for length; and - the assembly base by way of one end is able to be fastened, in particular screwed, to and/or on a rafter of a roof, and by way of another end is able to be fastened, in particular screwed, to and/or on an adjacent rafter of the roof; - the securing element by means of holding means is releasably fastened to the telescopic assembly base; - the holding means have a clamping element and a mating clamping element, the two latter (100, 110) being able to be connected to one another in such a manner that the clamping element and the mating clamping element jam a portion of the assembly base, wherein the clamping element and the mating clamping element are connected by means of at least one screw connection which by tightly screwing the clamping element and the mating clamping element to one another enables the assembly base to be jammed therebetween; - the connector device that permits mechanical coupling to the external securing means comprises an eyelet or is formed by an eyelet which is attached indirectly or directly to that end of the securing element that is distal from the assembly base; and - the other end of the securing element, thus the end of the securing element that is proximal to the assembly base, is fastened to the clamping element, characterized in that - the mating clamping element is formed by a component that is U-shaped in cross section.