In this study, the influence of bathing and use of ventilation equipment on thermal environment and amount of moisture produced in the bathroom were experimentally investigated. With the ventilation operating and the showering in the bathroom, the temperature differed by 2° for summer conditions, 5°C for winter conditions and 4°C for winter conditions. Regardless to the use of ventilation and the season, the humidity within the bathroom immediately reaches 100% after using the shower. For each of the seasons, from 900 to 1300g (1100g average) of moisture was produced by bathing, in which moisture attached to the surface accounted for about half of the total and moisture released from the ventilation accounted for the remaining half. The amount of moisture remaining was less than 40g which was extremely low in proportion compared to other moisture production.