The present invention relates to a procedure for irreversibly transferring a diffraction grating, such as a stamped hologram, onto a substrate, such as a document or a product to be secured, which procedure consists of preparing a transfer film consisting of a supporting film substrate that carries at least one layer formed by a protective film overlay, a metallized or transparent reflective layer that carries the stamped optical image, and a layer of activatable adhesive. The procedure consists of superimposing the transfer film prepared in the above-described manner and of applying pressure with a transfer tool. The stage consisting of the preparation of the transfer film consists of depositing, onto a supporting film substrate whose dimensions are greater than those of the element to be transferred, at least one optical element whose dimensions correspond exactly to those of the element to be transferred onto the substrate. The transfer tool acts on a portion of the transfer film whose dimensions are greater than those of the surface that corresponds to the element to be transferred. The invention also relates to a transfer film and to a tool for the implementation of the procedure.