To provide a coffin which prevents generation of harmful substances at cremation, has a good appearance, and also can prevent infections from the body.

The main body 10, the lid 60, and accessories are made of materials which do not generate harmful substances such as dioxins or sulfurous dioxide. On the main body 10 or the lid 60, an opening 35 is provided through which dry ice can be picked out. The fixing unit 41 which fixes the bottom 11 of the main body 10 and the longer side 21, is composed of the fixing groove 42 provided at both sides of the bottom, and the fixing hook 45 provided at the lower end of the inner surface of the longer side, which is fixed by sliding horizontally after fitting into the fixing groove 42. The inserting unit 51, which fixes the longer side panel 12 and the shorter side panel 31 together is configured with the fixing groove 52, provided at the both longitudinal end surfaces 33 of the shorter side panels 31 with the upper part of the end surfaces left undone, and the fixing projections 54 provided at the both longitudinal end surfaces of the longer side panels 21 with then upper part of the end surfaces left undone, so that they fit into the fixing groove 52.