<p>The mattress (1) has an intermediate layer (4) including grooves (7) on upper- and lower sides, where the grooves are intersected and passed with each other in depth. A hole-like passage (9) is formed between the grooves. The grooves are arranged between the elevations (8) of the intermediate layer on the both sides, so that the intermediate layer is chopped from slab-stock foams on the sides, where the sides have same breadth and depth. The grooves and the elevations are formed as cross sectional wave shaped and inclinely pass through an edge of the intermediate layer.</p>
