A member information management system stores data of second stage groups H and I and second stage groups J and K and data of members belonging to these second stage groups in a data protection area corresponding to each of a plurality of first stage groups A and B. The data of the second stage groups H, I, J, and K includes presentation data of a registration form of the second stage group and contents data for the second stage group. The member data includes specific data for specifying the second stage group H, I, J, or K. When a login operation of an administrator is successfully authenticated by administrator authentication information stored in an administrator protection area corresponding to the first stage groups A and B, browsing of predetermined data in all protection areas of the plurality of first stage groups A and B is permitted.