Abstract: An electric spark building-up of metal on the working surfaces of rolls is effected by applying a voltage from an unipolar current source to each roll being treated and to an electrode interacting with the surface of the rolls. Building up of metal is effected continuously in the course of operation, the rate of the metal build-up exceeding the rate of wear of the roll surface until a limit layer of metal is formed the thickness of which is maintained constant, thereby maintaining the initial shape of the roll working profile. The device for electric spark treatment is mounted on the rolling stand so that the electrodes and sliding contacts are in contact with the rolls, the electrodes interacting with the working surfaces of the rolls.