1. A foldaway security shutter comprising a plurality of transversal elements articulated between them by means of connecting rods hinged by the extremities of said transversal elements, two lateral uprights inside which the extremities of the transversal elements and the connecting rods slide between a position of closure in which said transversal elements are outstretched along the uprights and an opening position in which the transversal elements are gathered in a superior box, and operation means of the transversal elements, characterized in that the box houses a horizontal inferior guide provided with a plurality of consecutive notches suitable for the temporary anelastic retainment of transversal elements.

2. The shutter according to claim 1, characterized in that said operation means are provided with a toothed wheel, operated by an electric motor, suitable for engaging the internal toothing of rack connecting rods causing the up and down operation of the transversal elements.

3. The shutter according to claim 1, characterized in that the operation means comprise a stop device provided with sensors suitable for monitoring load variations in respect to regular working operation parameters memorized in a control unit.

4. The shutter according to claim 1, characterized in that the transversal elements present alternatively extremity long pins and extremity short pins, the former ones entering by contact in the horizontal inferior guide, the latter ones following a superior draft, causing the folding of the shutter.

5. The shutter according to claim 1, characterized in that the upright and the inferior guide are connected by connectors made of plastic material.

6. The shutter according to claim 1, characterized in that it comprises a system of lubrication.

7. The shutter according to claim 1, characterized in that it comprises cleaning brushes inside the uprights.

8. A method of folding in a box with an horizontal guide of transversal elements connected by connecting rods of a foldaway security shutter, characterized in that it provides the temporary anelastic retainment of transversal elements in a plurality of consecutive notches obtained in the horizontal guide, a transversal element being removed from the notch in which it is retained by a following transversal element which occupies the notch left free by the removed transversal element which moves towards a subsequent notch of temporary anelastic retainment.