Fall protection device (10, 11, 12) having a mounting base, a securing element connected to the mounting base and a connecting device attached to the securing element, which permits a mechanical coupling to an external securing means, in particular a rope or hook, - the mounting base being telescopic and length-adjustable, and - it being possible to fix, in particular screw, the mounting base by one end to and/or on a rafter of a roof and by another end to and/or on an adjacent rafter of the roof, - the securing element being detachably fixed to the telescopic mounting base by holding means, - the holding means having a clamping element and a mating clamping element, which can be connected to each other in such a way that the clamping element and the mating clamping element clamp in a section of the mounting base, the clamping element and the mating clamping element being connected by means of at least one screw connection, which permits the mounting base to be clamped in between the clamping element and the mating clamping element by screwing tight, - the connecting device permitting a mechanical coupling to the external securing means comprising an eye or being formed by an eye, which is attached indirectly or directly to the end of the securing element that is remote from the mounting base, and - the other end of the securing element, that is to say the end of the securing element that is close to the mounting base, being fixed to the clamping element, characterized in that - the clamping element and the mating clamping element are formed by a component that is U-shaped in cross section, in particular a U-shaped die-cast or extruded profile part, which has two parallel end sections and a support plate connecting the two parallel end sections, - the two end sections each form an outer supporting wall, which is supported on the mounting base, and - the plane of the support plate is located parallel to the longitudinal direction of the mounting base. - the mounting base being telescopic and length-adjustable, and - it being possible to fix, in particular screw, the mounting base by one end to and/or on a rafter of a roof and by another end to and/or on an adjacent rafter of the roof, - the securing element being detachably fixed to the telescopic mounting base by holding means, - the holding means having a clamping element and a mating clamping element, which can be connected to each other in such a way that the clamping element and the mating clamping element clamp in a section of the mounting base, the clamping element and the mating clamping element being connected by means of at least one screw connection, which permits the mounting base to be clamped in between the clamping element and the mating clamping element by screwing tight, - the connecting device permitting a mechanical coupling to the external securing means comprising an eye or being formed by an eye, which is attached indirectly or directly to the end of the securing element that is remote from the mounting base, and - the other end of the securing element, that is to say the end of the securing element that is close to the mounting base, being fixed to the clamping element, - the clamping element and the mating clamping element are formed by a component that is U-shaped in cross section, in particular a U-shaped die-cast or extruded profile part, which has two parallel end sections and a support plate connecting the two parallel end sections, - the two end sections each form an outer supporting wall, which is supported on the mounting base, and - the plane of the support plate is located parallel to the longitudinal direction of the mounting base.