This paper describes an analysis of the survey on window opening/closing in dwellings in the Tokyo metropolitan area. Questionnaires were delivered through internet twice in 2008. Each time 1000 homemakers answered -a half of them lived in single houses and the others in apartment houses. Results of the survey are as follows,
1. 94% homemakers had the attitude to open the windows of their houses, and 95% of them opened the windows.
2. From 11 to 18% of the homemakers who didn't have the attitude to open the windows actually opened the windows.
3. Approximately 40% homemakers felt the obstacles to open the windows, and 86% of them opened the windows.
4. On August, from 17 to 39% of the homemakers opened the windows in the nighttime and from 40 to 67% of the homemakers opened the windows in daytime.
5. In case of the outside temperature was lower than 28°C, number of the homemakers who opened the windows were larger than they who turned on the air conditioners.
