The invention concerns an operating device comprising an elevator door (2) folding around a vertical axis during its opening or closing movement. The invention is characterised by the following three characteristics: a) the vertical axis (4, 6) constitutes also the dragging element of the door (2) of the elevator cabin (1), b) the door (2) of the cabin (1) is constantly subject to a tractive force that tends to close it, c) the vertical axis (4, 6) comprises a motor with external rotor and internal stator. The invention allows to realise elevator doors (2) of minimal overall dimension, since they lack the space to be allocated to the motor for dragging the door - as usually necessary -, of easy assembly and of optimal packing and transport conditions.