A securing device for securing a person has an axle element attached torque-proofly to a rope drum and rotatably to a support structure, such that, by the axle element, the rope drum is supported rotatably at the support structure. A lever is attached pivotably to the support structure at a deflection point. In a blocking position of the lever, a blocking section is coupled to the rope drum in order to disable a rotation of the rope drum, and in a releasing position of the lever, the blocking section is decoupled from the rope drum and the rope drum is rotatable. A thread section of the lever is coupled to a further thread section of the axle element, such that, upon rotation of the axial element, due to the rotation of the rope drum, the thread section is shifted along the axle element, such that, due to the shifting of the thread section, a rotation of the lever around the deflection point and an adjustment between the blocking position and the releasing position of the lever are effected.