Abstract: A method for regulating the parameters of thermal cycles in electroslag welding in which the entire area of the zone affected by heating is cooled. The area is limited by isotherms of maximum heating temperatures within an interval from temperatures close to the melting temperature point up to a temperature A.sub.1. The cooling is effected so that the cooling rate would increase in the direction of movement away from the area heated up to the melting point towards the area heated up to the temperature A.sub.1. The device for realizing the method of regulating the parameters of thermal cycles has jets secured on the side and bottom faces of the slide block, with outlet spraying nozzles for the jets located such that the cooling medium flowing out from those nozzles would cool the entire surface of the metal of the seam and the zone subject to heating effect the surface is limited by the isotherms of maximum heating temperatures within an interval from the melting point up to the temperature A.sub.1.