Abstract: A plant for electrolytic surface treatment and especially for descaling of a metal strip (2), comprising for the treatment of the same single face of the strip, at least two electrode-rolls (4) which are entirely immersed in a bath of electrolytic liquid and over which the strip passes. The rolls are covered with an insulating coating consisting of a series of spaced bearing rings centered in planes perpendicular to the axis of the roll and between which are provided annular treatment spaces, the bottom of which consists of a conductive wall, and the bearing rings are offset axially from one roll to another so that, in the direction of travel of the strip, the regions treated between the bearing rings of one roll correspond to the bearing regions on the rings of the succeeding roll, and vice versa. The plant can be applied, for example, to the cleaning, pickling or dechroming of a strip travelling at a high speed.