Apparatus for positioning electrical components relative to a carrier so that the articles can be laid down and attached at predetermined locations on the carrier comprises a first reference system defined by a first plurality of at least three fixed points, first means for bringing the carrier to position in relation to said first reference system such that lateral edges of the carrier come to bear against said first plurality of points, a second reference system defined by a second plurality of at least three fixed points, second means for defining on the carrier, when it is in said position, the locations for the articles to be laid down on the carrier, means for positioning the articles to be laid down in predetermined positions corresponding to the defined locations, and said second reference system being superimposed over said first reference system so as to enable the carrier to be positioned in relation to the said articles in such a way that the articles are then exactly opposite the defined locations for them on the carrier wherein the first means includes at least three rotatable abutments corresponding to the fixed points and being adapted to press the lateral edges of the carrier against the aforementioned fixed abutments.