To attach/detach a rack as needed by freely attachably and detachably fitting a rack through a stopper to the upper part of bed frame surrounding the outer periphery of mat body.

When attaching a rack 4 to the upper part of bed frame surrounding the outer periphery of mat body, the rear part of rack 4 is placed on an upper lateral frame member 27 of a short side frame part 9 on one side and respective holes 36 on the rack 4 are matched with the position of a hole 32 formed on the upper lateral frame member 27. Then, a nut 34 is inserted from the downside to the hole 32 on the upper lateral frame member 27, the head of bolt 38 is inserted into the hole 36 of rack 4 and the bolt 38 is screwed into the nut 34 so that the rack 4 is freely attachably and detachably fixed outward or inward to the upper lateral frame member 27. Thus, the rack 4 is attached or detached as needed and even in a narrow room, a baby bed is installed only by changing the attaching direction of rack 4.