Process for changing an anode of a cell for the production of aluminum by fused bath electrolysis, each anode comprising at least one anode block (21, 21', 21") and a metal rod (22, 22', 22") and being fixed removably to a mobile metal frame, each anode block having a reference surface (21a, 21a', 21a"), process by which at least one determined spent anode is replaced by a replacement anode (20") using at least one anode handling tool comprising a positioning device, a gripping device and a position sensor to determine the vertical position of the gripping device, wherein the position sensor of the anode handling tool or each anode handling tool is used to measure the vertical distances traveled by the gripping device or each gripping device relative to a reference level N, and wherein at least one beam of sound or electromagnetic waves is produced along a determined reference axis or in a determined reference plane, and in that for each determined spent anode; said process comprising the following steps: a) said gripping device is placed in the gripping position of the metal rod of said spent anode, and the vertical distance A traveled by the gripping device to reach said position is measured; b) the spent anode is withdrawn from the electrolytic cell, the anode block of this anode is passed through said beam in a vertical movement and the vertical distance B traveled by the gripping device at the moment at which the reference surface of this anode passes through the beam is measured; c) the metal rod (22") of said replacement anode (20") is gripped using said gripping device, the anode block (21") of this anode is passed through said beam in a vertical movement and the vertical distance C traveled by the gripping device at the moment at which the reference surface (21a") of this anode passes through the beam is measured; d) the vertical position of the replacement anode (20") in the cell is determined starting from values obtained for the traveled distances A, B and C, and the replacement anode (20") is put into this position in the place initially occupied by the spent anode; said process being characterized in that said vertical position sensor is integrated into the anode handling tool and in that the spent anode is laid down and the replacement anode is taken with the help of said handling tool in a determined place, said beam being set at a determined height above said determined place, typically a temporary stocking area, so that said measures of the vertical distances B and C are made respectively when said spent anode is laid down and when said replacement anode is taken in said determined place. a) said gripping device is placed in the gripping position of the metal rod of said spent anode, and the vertical distance A traveled by the gripping device to reach said position is measured; b) the spent anode is withdrawn from the electrolytic cell, the anode block of this anode is passed through said beam in a vertical movement and the vertical distance B traveled by the gripping device at the moment at which the reference surface of this anode passes through the beam is measured; c) the metal rod (22") of said replacement anode (20") is gripped using said gripping device, the anode block (21") of this anode is passed through said beam in a vertical movement and the vertical distance C traveled by the gripping device at the moment at which the reference surface (21a") of this anode passes through the beam is measured; d) the vertical position of the replacement anode (20") in the cell is determined starting from values obtained for the traveled distances A, B and C, and the replacement anode (20") is put into this position in the place initially occupied by the spent anode;