The invention relates to a method for producing a sealing base in the ground in which by injection of a curable grouting compound a plurality of sealing elements is produced in a first soil layer, which elements adjoin one another or overlap, wherein the plurality of sealing elements forms a solid base plate following curing of the grouting compound. It is provided according to the invention that in a second soil layer, which lies beneath the first soil layer for the solid base plate, a gel base is created by injection of a sealing gel, and that the solid base plate and the underlying gel base form the sealing base. The invention further relates to a correspondingly produced sealing base.