The present invention relates to a device for the continuous monitoring of current distribution in the cathodes and anodes of an electrolyser comprised of at least two adjacent electrolytic cells, each containing a multiplicity of said cathodes and anodes. The device according to the invention is composed essentially of at least one current-collecting bus-bar having housings suitable for supporting the electrodes and a base of insulating material whereon the bus-bar abuts. The base has integrated probes for measuring voltage. The invention also relates to a permanent monitoring system allowing to evaluate in continuous current distribution on each electrode in cells used in particular in metal electrowinning or electrorefining. The invention also relates to a method for retrofitting of an electrolyser comprising the replacement of an existing insulating base with a new base element having integrated probes for measuring voltage.