An information management terminal device includes a health information acquisition means, a health information storage means that stores health information and a health information passbook, and a storage medium, in which the storage medium includes a concealed region accessible only by a specific program and a normal region accessible also by programs other than the specific program, the health information acquisition means adds a date/time record as the health information passbook, the health information storage means sequentially stores the health information and the health information passbook in the normal region, and that the concealed region holds a data alteration detection parameter for detecting alteration of the health information and/or the health information passbook.