Abstract: A step or rung ladder is disclosed, which can be folded together into a compact unit under transport. The step or rung ladder includes two step frame sections (1, 2) connected by lockable hinges (3, 3?), and two support frame sections (9, 6) also connected by lockable hinges (8, 8?). The step frame is connected to the support frame in its upper end by hinges (15, 15?). A support or safety rail is connected to the upper end of the step frame, either rigidly or by a third set of lockable hinges (10, 10?).