To provide a mattress with freely foldable performance by using hard cotton produced by a cross lay method.

In the freely-foldable mattress using the hard cotton obtained by laminating webs containing low melting point fibers and matrix fibers and heat setting, the hard cotton contains the low melting point fibers by 5 to 40 mass %, 0.55 to 4.4 dtex matrix fibers by 5 to 40 mass % and 5.5 to 22 dtex matrix fibers, whose coefficient of inter-fiber static friction is equal to or lower than 0.2, by equal to or larger than 5 mass %, folding property of the hard cotton by the cantilever method is equal to or shorter than 60 cm, and the separation strength holding rate of the hard cotton after a folding test is equal to or higher than 90%.