Fusuma is a type of sliding doors used in Japanese traditional architecture. Fusuma consists of a self-supporting wooden frame and a surface material made of several layers of paper that is often painted. Fusuma are often conserved and exhibited inside buildings such as castles and temples where the temperature and humidity are not controlled. In such environments, differences in temperature and humidity on the two sides of Fusuma often occur, causing their warping and paper tear. However, the mechanism and the relationship between the deterioration of Fusuma and the hygrothermal environment have not yet been clarified. Herein, we aimed to elucidate the physical deterioration mechanisms of Fusuma under conservation and exhibition conditions. In this study, we prepared a Fusuma and placed it in a twin-chamber in which temperature and humidity can be controlled. One side of Fusuma was always kept dry, while the other side was repeatedly exposed to dry and wet conditions. The hygrothermal conditions were assumed to be the actual environment in which Fusuma are exhibited: 30 ℃ and 60% RH for the dry conditions, and 23 ℃ and 90% RH for the wet conditions. The following results were obtained. (1) Fusuma warped toward the wetter environment, and (2) the deformation of the paper was consistent with that of the frame. The latter result cannot be understood without considering the structure of Fusuma. Repeated dry/humid experiments showed little residual strain on the paper under the conditions of this experiment.