PURPOSE: To provide a mattress system which can be taken apart easily at the time of dismantling.

CONSTITUTION: The mattress is composed of the exterior body 7 constituted by the spring units 1 having the upper and bottom faces, the fillings 6 placed in layer outside of said upper and bottom faces of the spring units 1, the panel sections 8 and 9 covering the upper and lower faces respectively of the layers of such fillings 6 and the spring units 1 and the border section covering the outer peripheral face, and a pair of flange cloth 12 provided upside and downside with one end of which is connected to the peripheral part of the inner face of the respective panel sections. Connecting materials 13 formed by a shape memory alloy are also provided discontinuously along the peripheral direction with its respective ends connected to the other ends of the pair of flange cloth on the upside and downside at the outer periphery of the spring units, attaching tension to the flange cloth by deforming its shape under heating.