Interface plate for alpine ski safety binding. The plate has an edge (3) extending along at least one portion of the lateral edges of the base. On either side of its median zone, the plate has a lateral element (5) which carries the edge (3). The lateral elements (5) are inclined substantially downward and outward from the plate, so that, when the binding base is assembled on the ski and the plate is clamped between the base and the ski binding, the lateral elements (5) straighten into a horizontal position, thus forcing the edges (3) to flatten along the lateral edges of the base.