PURPOSE: To enable a barrel to be stacked on another barrel, when the former barrel having a removable cover therein is transported with its contents empty.

CONSTITUTION: A main body 10 of this barrel has a diameter at its base section 18 smaller than that of an upper loading hole 16 and a diameter expanded section 12 with a steep step at the third region counted from the upper section Consequently, a side surface 14 of the barrel projects substantially perpendicular to the barrel in a continuous manner up to the upper loading hole 16, thereby a space is formed between the lower barrel and the upper barrel stacked into the lower barrel, so that it is possible to prevent some barrels stacked to each other from being fixed under their wedge action.