A loading device for cargo spaces in transportation means, in particular for cargo spaces in aircraft, includes a roller conveyor that contacts a substructure in a first position for placing cargo units in the cargo space. In one embodiment, the roller conveyor has contact surfaces on both sides and the substructure 3 is formed as a U-profile having a base and two webs. Both webs of the U-profile have bearing surfaces oriented at least partially inwardly and the contact surfaces are formed, such that they cooperate with the bearing surfaces in the first position and in a second position. In the second position, the roller conveyer 2 is insertable into the substructure for forming a substantially flat base surface of the cargo chamber, which serves in particular for placing vehicles into a cargo space.