The invention relates to a sectional element mat (2), the support properties of which may be individually tailored, whereby exchangeable sectional elements (E) are arranged tightly together or above each other. The above is characterized in that the individual sectional elements (E) may be easily removed and exchanged with other sectional elements. The individual sectional elements are either connected to each other by means of a separable material bridge or perforation (5, 6), connected to each other by means of a plug connector (27, 31), plugged onto or into a common base mat (40) or lying loose on the same. Individual sectional elements can be removed or separated from the combination where necessary and replaced by softer or stiffer sectional elements. In certain situations the resulting free space is left empty. The sectional element mat (2) is either part of a combination with other sectional element mats or contiguous or separate layers (1, 3), or itself forms the mattress core.