The invention relates to a method for the production of molded parts having a front face and a back face made of a hardenable reaction material, whereby a casting mold consisting of several mold parts is formed, said casting mold having a configuration that remains substantially unchanged during a molding and hardening step and forming a cavity into which the reaction material is filled and hardened, whereupon the casting mold is opened and the molded part is removed from the casting mold. At least one casting mold part has a deformable surface and the cavity of the casting mold is filled with a predetermined amount of hardenable reaction material from a reservoir. The reaction material is hardened while the volume of the cavity of the casting mold is reduced by deformation of the deformable surface of the casting mold. The invention is characterized in that a deformable casting mold surface is used, which is formed by a metal layer and in that the metal layer is kept in contact with the reaction material during deformation of the deformable casting mold surface. The invention also relates to a corresponding device for implementing the method disclosed in the invention.