To provide an ecological and useful coffin capable of eliminating the possibility of dewing on its outer face and grow of tears, of damaging incinerator with burning heat in cremation and of exhausting harmful substances into the air.

A foamed sheet 21 which contains microballoon formed by heat foaming of heat foamed microcapsule and has a heat conductivity of 0.030-0.060 kcal/m.h.C-degree, a bulk density of 0.05-0.35 g/cm3 and a static friction coefficient of 1.1-4.0 is fixed to the inner face of a box 7 for a coffin 1 formed with side plates and a bottom plate, having its upper face open. Waterproof treatment with water-proofing agent is given to the sheet surface of the foamed sheet, opposed to the inner face of the box 7.