The invention concerns a mobile furniture device for space management, comprising two outer enclosing parts (1, 2) mobile relatively to each other, said parts being capable of being assembled in a storage position, to form together a hollow container defining within a closed volume wherein are housed several items of furniture. The invention is characterised in that at least one of the furniture items is mobile (6-13) and independent of said parts, and said parts comprise a housing (4, 5) opening onto the side wall and shaped for receiving at least partly said mobile component, said housing being designed to be closed by another of said enclosing parts to close inside said container the set of said furniture items, said mobile item being capable of being removed or spaced by rolling said housing, into a position for use, wherein the enclosing parts are extended.