Folding stairs, wherein the folding stairs comprise: at least one step comprising an upper side and a lower side, a holding system being adapted to hold the at least one step, wherein the at least one step is movably attached to the holding system, wherein the folding stairs comprise an unfolded state and a folded state, wherein the holding system is adapted to attach the folding stairs to a vertical wall such that in the unfolded state the upper side of the at least one step is horizontally aligned to form a climbing aid and in the folded state the lower side of the at least one step is aligned parallel with the wall, characterized in that the holding system further comprises: a fastening element, wherein the fastening element is adapted to attach the folding stairs to the wall, and a supporting element, wherein the supporting element is adapted to support the at least one step in the unfolded state, wherein the supporting element is attached to the fastening element by means of a slidable hinge, and the slidable hinge is arranged to allow a sliding motion of the supporting element vertically along the fastening element, wherein the fastening element comprises a rail portion, wherein the supporting element is attached to the rail portion of the fastening element by means of the slidable hinge, and the supporting element is adapted to move along the rail portion by means of the slidable hinge during a transition between the folded and the unfolded state. at least one step comprising an upper side and a lower side, a holding system being adapted to hold the at least one step, wherein the at least one step is movably attached to the holding system, wherein the folding stairs comprise an unfolded state and a folded state, wherein the holding system is adapted to attach the folding stairs to a vertical wall such that in the unfolded state the upper side of the at least one step is horizontally aligned to form a climbing aid and in the folded state the lower side of the at least one step is aligned parallel with the wall, characterized in that the holding system further comprises: a fastening element, wherein the fastening element is adapted to attach the folding stairs to the wall, and a supporting element, wherein the supporting element is adapted to support the at least one step in the unfolded state, wherein the supporting element is attached to the fastening element by means of a slidable hinge, and the slidable hinge is arranged to allow a sliding motion of the supporting element vertically along the fastening element, wherein the fastening element comprises a rail portion, wherein the supporting element is attached to the rail portion of the fastening element by means of the slidable hinge, and the supporting element is adapted to move along the rail portion by means of the slidable hinge during a transition between the folded and the unfolded state. a fastening element, wherein the fastening element is adapted to attach the folding stairs to the wall, and a supporting element, wherein the supporting element is adapted to support the at least one step in the unfolded state, wherein the supporting element is attached to the fastening element by means of a slidable hinge, and the slidable hinge is arranged to allow a sliding motion of the supporting element vertically along the fastening element, wherein the fastening element comprises a rail portion, wherein the supporting element is attached to the rail portion of the fastening element by means of the slidable hinge, and the supporting element is adapted to move along the rail portion by means of the slidable hinge during a transition between the folded and the unfolded state.