Help, Floating object in the air

Hello, can some1 tell me how i can place objects in the air, so they stay in the air.
Does it have to be an object, which i import myself into the game? If i try the container it lands everytime on the ground.

For example something like this in the air:

 

If you dont want to use world Editor, you can free cam the thing into the air, slow down the Game, Press Control and left click on a node. Pull the node and right click into the air. There should be a black line with orange dots on both ends. Do that with every corner, end slow motion and the object should stay in the air