PURPOSE:To obtain a roomy merchandise display hall that can be formed at any place by forming its roof and floor by developing car-body side boards in three directions; namely, the right, left, and back, and by spreading out side panels onto the roof and floor as necessary. CONSTITUTION:At the top brim of both sides of box-shaped body 1, the top end of a side roof 2 is pivotally supported, while at the bottom brim, the bottom end of a side floor 3 is pivotally supported. The side roof 2 and the side floor 3 are linked together in such a manner that each plurality of them can be folded. Each one end of roof supports 4a and 4b that can be opened in the horizontal direction and in a rotary manner is pivotally connected to the both forward and afterward ends of the top brim of the box-shaped body 1, while each one end of floor supports 5a and 5b that can be opened in a rotary manner is pivotally connected to the forward and afterward ends of the bottom brim of the box- shaped body 1. The roof supports 4a and 4b and the floor supports 5a and 5b are structured in such a manner that their lengths are adjustable to meet the widths of the side roof and the side floor that are to be spread out.