To provide a lightweight built-up type coffin usable especially at the time of urgent calamity, with enhanced strength and rigidity, excellent in the heat insulation and water imperviousness, to be easily assembled with a small number of people and compactly stored in a mass.

The coffin comprises a pair of first side panels 1 and a pair of second side panels 2 made of corrugated cardboard with irregularity portions at three side ends, a base board 3 made of corrugated cardboard with irregularity portions at side ends of four peripheral edges, a first belt-shaped connection material 4 for connecting the first side panels 1 and the base board 3, a second belt-shaped connection material for connecting the second side panels 2 and the base board 3, and a lid board made of corrugated cardboard. The first belt-shaped connection material 4 and the second belt-shaped connection material are pasted on prescribed positions. Each first side panel 1 is folded to the outer side or the inner side of the base board 3 in the layered state via the first belt-shaped connection material 4, and each second side panel 2 is folded to the opposite side of the base board 3 to the first side panel 1 via the second belt-shaped connection material.