To provide a coffin which is made of a foamed resin, is good in a thermally insulating characteristic so as to be suitable for cold retaining of a corpse, has good moldability, makes it possible to obtain perfect moisture- and waterproofing properties, is free of a possibility of a hospital infection, is further immediately burned out by the heating power of burners during cremation, allow the fires of the burners to spread to the corpse immediately and does not leave ash.

A body 1 and a cap 2 of the coffin P made of the foamed resin is molded of the completely lost foam resin material which has good foamability and moldability and enumerates less carbon and gases at the time of incineration. The foamed resin material consists of a lost foam acrylic foamed resin material consisting essentially of methacrylate. Examples of the foaming agent includes propane, butane methylene chloride, and more particularly pentane is liquid pentane, and under ordinary temp. and atm. pressure and is preferable in terms of its retain ability of the foamability.