The invention relates to a wall (100) of a casting die for casting a molten metal. Die walls comprising a front plate (110) with a pocket borehole (112) and a rear plate (120) with a transversal borehole (122) aligned with the pocket borehole, on the cold side of the die front plate, are known in prior art. The aim of the invention is prevent the entrance of cooling liquid from the transition region (115), between the front plate (110) and the rear plate (120), into the pocket borehole (112) or the transversal borehole (122). To this end, a sealing element (140) having a longitudinal borehole is arranged in the transition region (115) in such a way that the longitudinal borehole of the sealing element is at least approximately aligned with the transversal borehole (122) in the rear plate of the die and the pocket borehole (112) in the front plate of the die.