To provide a structure of an inner wall and a reconstruction method using the inner wall enabling easy formation of a new opening such as a door or the like in the inner wall with a small labor, reduction in construction period, and cost reduction, in remodeling the inside of a building.

The inner wall comprises adjacent wall panels 11A and 11B arranged at a predetermined interval of a plurality of wall panels 11 interconnected horizontally, an opening substrate 20 capable of supporting an opening frame material 18 disposed between the adjacent wall panels 11A and 11B, an opening face plate for covering the opening substrate 20, and an adjusting panel 30 disposed in a part between the adjacent wall panels 11A and 11B except the opening substrate 20. Removing the opening face plate exposes the opening substrate 20, so that the opening frame material 18 can be easily mounted to the opening substrate 20 and the construction period can be shortened.