A confidential information setting method for setting confidential information to a terminal by using a server, a user apparatus, and a confidential information storage apparatus when an initial key for securing communication is not available, wherein the user apparatus: acquires an encrypted terminal secret key from a memory unit of the server, encrypted with an encryption key, and stores it within encrypted secret key storage table as a terminal secret key; and acquires a terminal ID, which is an identifier for uniquely identifying the terminal, from the terminal; and wherein the confidential information storage apparatus: acquires the encryption key and condition information, which is a condition for setting the secret key to the terminal and comprises information to be acquired by the user apparatus from outside of the user apparatus, from the memory unit of the server, and stores them as encryption key and condition information in information storage table; acquires (S206, S207) the terminal ID and the terminal secret key, associated with an entry ID related to the terminal ID and encrypted, from a memory unit of the user apparatus; decrypts the encrypted terminal secret key with the encryption key, and stores the decrypted terminal secret key in terminal secret key storage unit; transmits, to user apparatus, a condition information ID associated with the entry ID; wherein the user apparatus then: judges the condition information ID received from the confidential information storage apparatus, acquires condition information, and transmits the acquired condition information to the confidential information storage apparatus; wherein the confidential information storage apparatus: receives, from the user apparatus, the acquired condition information and compares the acquired condition information with the condition information; judges whether the decrypted terminal secret key, stored in the terminal secret key storage unit, can be set to the terminal or not, based on the comparison of the acquired condition information with the condition information; and when a result of the judgment indicates that the secret key can be set to the terminal, sets the secret key to the terminal by transmitting a terminal setting public key to the terminal and establishing encrypted communication between the confidential information storage apparatus and the terminal, and transmitting the terminal secret key to the terminal. acquires an encrypted terminal secret key from a memory unit of the server, encrypted with an encryption key, and stores it within encrypted secret key storage table as a terminal secret key; and acquires a terminal ID, which is an identifier for uniquely identifying the terminal, from the terminal; and acquires the encryption key and condition information, which is a condition for setting the secret key to the terminal and comprises information to be acquired by the user apparatus from outside of the user apparatus, from the memory unit of the server, and stores them as encryption key and condition information in information storage table; acquires (S206, S207) the terminal ID and the terminal secret key, associated with an entry ID related to the terminal ID and encrypted, from a memory unit of the user apparatus; decrypts the encrypted terminal secret key with the encryption key, and stores the decrypted terminal secret key in terminal secret key storage unit; transmits, to user apparatus, a condition information ID associated with the entry ID; judges the condition information ID received from the confidential information storage apparatus, acquires condition information, and transmits the acquired condition information to the confidential information storage apparatus; receives, from the user apparatus, the acquired condition information and compares the acquired condition information with the condition information; judges whether the decrypted terminal secret key, stored in the terminal secret key storage unit, can be set to the terminal or not, based on the comparison of the acquired condition information with the condition information; and when a result of the judgment indicates that the secret key can be set to the terminal, sets the secret key to the terminal by transmitting a terminal setting public key to the terminal and establishing encrypted communication between the confidential information storage apparatus and the terminal, and transmitting the terminal secret key to the terminal.