The invention relates to a security element for an article to be protected, having an upper face and a lower face, one or more imaging optical arrangements, which all image a respective associated object to a magnified scale only in front of the upper face, wherein the one optical arrangement or at least one of the optical arrangements comprises a plurality of reflective micro-imaging elements arranged two-dimensionally in a first pattern, and the associated object is in the form of a microstructure object having a plurality of microstructures, which are arranged in a microstructure pattern so matched to the first pattern that the microstructure object is imaged to a magnified scale in front of the upper face by means of the reflective micro-imaging elements. On both its upper face and its lower face the security element has an adhesive layer (14, 16), with which the security element can be embedded in the article to be protected such that both the upper face and the lower face are adhesively secured to the article to be protected.