PURPOSE: To efficiently use the resident space of a vehicle by bendably connecting divided floor parts capable of being divided into at least two parts, loading a first floor part so that it can be turned from a vertical state to a lateral horizontal state and mounting a stay which regulates and supports a second floor part between the first and second floor parts.

CONSTITUTION: When a bed 1 set in a folded state is changed to an available state, the first floor part 3a held in the vertical state is drawn out, and it is set so as to be opened in the lateral horizontal state. At this time, the second floor part 3b supported in a horizontal state originally is moved in a lateral direction with the first floor part 3a as keeping the horizontal state via the stay 6 and a spring member 7, and both the floor parts 3a, 3b form one flat floor part 3 finally. While, when the bed is unused, the first floor part 3a is lifted, and the second floor part 3b is bent for the first floor part 3a, and also, it is housed in the upper part of the first floor part 3a returned to the vertical state as keeping the horizontal state by the stay 6 and the spring member 7.