To improve an air-tightness of a double folding door of a refrigerator container, substantially restrict a leakage of cold air, eliminate a center pillar and facilitate a loading or an unloading of cargo into or out of the container.

A sectional shape of an opening or closing end 24 of each of double folding doors 13a, 13b is of a complementary shape. A packing 25 having such a sectional shape coming into contact with an end edge of a gasket 14 extending along one side surface and fixed to a surface opposing against the opening of the door in a container main body is adhered to one side surface of the complementary shape. The material for it is of a foamed resilient plastic material having closed air bubbles.