Abstract: In the case of a mattress provided with holding elements, a layer can be put on, which layer is provided with fixing means, the layer being removably attached to the mattress. The holding means comprise a long stretched-out, substantially longitudinally stable, flexible element, of which in each case two first regions are connected to the mattress, while second regions, situated in-between, are free. The respective spacing between two second regions is substantially constant; the fixing means are installed on the layer such that they each come to lie at a second region of the holding elements. The fixing means are connectible to the corresponding second regions of the holding elements. With this system, layers can be connected to the mattress in the simplest way.