Self-locking device for securing and/or lowering a user along a rope, comprising a body, a release mechanism and an anti-panic mechanism, the body comprising a first and a second plate, a lever member, a sliding profile, wherein the first and second plates are both fixed, substantially parallel to one another and connected together at one end through the lever member hinged to both of the plates (2,3) through a pin and on the opposite end through the sliding profile, so that, when assembled, said plates (2,3) define a space (d) in which a path for the rope is defined, said lever member also comprising a fixed pulley, arranged on a portion of said lever member that does not comprise the tilting pivot, said rope being intended to slide on said fixed pulley about an axis offset with respect to the axis of the tilting pivot of the lever member, said lever member being able to tilt between a release position in which the rope is free to slide within the device and a holding position of said rope in which the rope is locked between the fixed pulley and the sliding profile, the lever member tilting between the release and holding position when the rope is put under tension, said first plate comprising an inner face and an outer face, said outer face comprising a housing for the release mechanism of the rope and the anti-panic mechanism, which release mechanism and anti-panic mechanism comprising: - a lever able to move together with the lever member and hinged at one end to the pin and comprising at the free other end a guide element which is able to rotate about a pin; - an elastic means that act in contrast to said lever for the return of the lever member from the holding position to the release position of the rope; - a handgrip comprising a plaque on which a cam member is hinged so as to be able to tilt, said cam member being able to interact with the guide element of the lever and wherein said plaque also comprises a pin intended to be housed in a slot of said cam member and determining the tilting stroke of the cam member. a first and a second plate, a lever member, a sliding profile, wherein the first and second plates are both fixed, substantially parallel to one another and connected together at one end through the lever member hinged to both of the plates (2,3) through a pin and on the opposite end through the sliding profile, so that, when assembled, said plates (2,3) define a space (d) in which a path for the rope is defined, said lever member also comprising a fixed pulley, arranged on a portion of said lever member that does not comprise the tilting pivot, said rope being intended to slide on said fixed pulley about an axis offset with respect to the axis of the tilting pivot of the lever member, said lever member being able to tilt between a release position in which the rope is free to slide within the device and a holding position of said rope in which the rope is locked between the fixed pulley and the sliding profile, the lever member tilting between the release and holding position when the rope is put under tension, said first plate comprising an inner face and an outer face, said outer face comprising a housing for the release mechanism of the rope and the anti-panic mechanism, which release mechanism and anti-panic mechanism comprising: - a lever able to move together with the lever member and hinged at one end to the pin and comprising at the free other end a guide element which is able to rotate about a pin; - an elastic means that act in contrast to said lever for the return of the lever member from the holding position to the release position of the rope; - a handgrip comprising a plaque on which a cam member is hinged so as to be able to tilt, said cam member being able to interact with the guide element of the lever and wherein said plaque also comprises a pin intended to be housed in a slot of said cam member and determining the tilting stroke of the cam member. - a lever able to move together with the lever member and hinged at one end to the pin and comprising at the free other end a guide element which is able to rotate about a pin; - an elastic means that act in contrast to said lever for the return of the lever member from the holding position to the release position of the rope; - a handgrip comprising a plaque on which a cam member is hinged so as to be able to tilt, said cam member being able to interact with the guide element of the lever