To provide an indoor reform method using regular hexahedron structures as basic materials for use in reforming a three-dimensional space in a freely utilizable manner including partitions in desirable shapes, wherein the indoor reform method is intended for a convenient tool for the effective use, including planar use (two-dimensional) and spatial use (three-dimensional), of rooms referred to as an efficiency apartment or the like wherein available floor surfaces are relatively limited.

Regular hexahedron structures are used as basic materials capable of constituting a partition structure, a storage box, a knockdown bed, and other arbitrary indoor fittings by arranging a required number of the regular hexahedron structures on the floor surface in a desired region of a room to be reformed, thereby enabling the indoor reform according to user's desire.