As a step toward formulating policy guidelines for planning and development, uses of inner-plaza atriums were examined to assess their public benefit. Twenty-two sample observation and interview surveys were conducted in the Kanto region. Three independent use-for-staying-space indices were extracted through factor analysis, and their explanatory variables were identified through multiple regression analysis: 1) the number of staying users, 2) the density of staying users and 3) the percentage of general visitors in staying users. As much as 90.3% of variance was explained. Use-for-staying-space indices thus proved to be explained by design factors such as the building area at an extremely, or at least fairly high level of precision.