The Empty Space Container is a treasure exclusive to the PAL version of Pikmin 2 it is a baby clam container. It is found on the 8th sublevel of the Cavern of Chaos. It is the 167th treasure on the List of Pikmin 2 treasures in the PAL version.
Captain Olimar's Journal
"When all these containers pile up in my ship, I start to wonder... would I be better off working as a treasure hunter or should I stay in the transportation business as always?"
"The interior of this container ignores the physical laws of size and became indefinite space. All objects placed in it become indefinitely big and indefinitely small."