To provide a rice cooking oven in which conveyance, assembling, and accommodation are simply achieved, and these works are smoothly done only with one person.

A rice cooking oven 11 is constructed by assembling division walls 12, 13, 14. Mutual adjacent ends of one set include upon assembling a hook lever 17 at the one end and a stopper piece 19 engaged with the hook lever on the other end. Mutual adjacent ends of remaining sets include upon assembling slidable holes 24 slidable along a divided wall body on the one end sides, and locking piece 26 engageable with a slidable hole peripheral edge on the other end sides. In assembling the locking piece 26 is engaged with the peripheral edge of the slidable hole 24, and the hook lever 17 is engaged with the stopper piece 19, and further the mutual divided walls are coupled into a substantially circular shape. In accommodation, the engagement of the hook lever 17 to the stopper piece 19 is released, and the other divided wall body is slided to the slidable hole 24. Further, the divided walls are laminated and accommodated.