PROBLEM TO BE SOLVED: To provide a personal authentication system and an operation prediction system having high user authentication accuracy and extremely inexpensive.SOLUTION: ID code information written into a wireless authentication IC chip provided for a user is subjected to an authentication process as complementary data of user information. This personal authentication system is composed of a card 1 including a noncontact IC chip with an external antenna, a reader- side antenna part 2, a reader part 3, an authentication function part 4 and a system apparatus part 5.