In recent years, the aspect and behavior inside a bathroom and an appurtenant changing room have been changing. With these changes, the thermal insulation quality of a dwelling has improved, so it seems that the amount of moisture generated in a dwelling has changed. In this study, amount of moisture produced in a bathroom and a changing room was surveyed in order to grasp the thermal and humid environment in bathroom and a changing room. From the result of the survey, it was found that the amount of moisture in bathing was bigger than before. It was considered that the amount of adhesion moisture was depended on the way of bathing, and the balance of exhausted moisture by ventilation and remaining moisture in the atmosphere was depended on of ventilation rate. The survey was conducted in two different size bathrooms (1200x1600, 1600x1600). Influence of a bathroom size was deliberated.