A secure, inexpensive, convenient
payment system which allows an existing communication to be used to make an expensive
payment terminal unnecessary, makes local communication unnecessary to make it possible to use the
system by a seller and a buyer, uses closed-loop type
electronic money to make it possible to make
payment on delivery is obtained. An account
database 6 which is arranged as equipment of a communication carrier and manages accounts of sellers and buyers (users), and a payment
server 5 which is arranged as equipment of the communication carrier and performs an electronic payment process between the seller and the buyer are arranged. In the payment
server 5, a primary payment
server 3 and a secondary payment server 4 are arranged. When a payment request from a user is received through a communication network 10, the primary payment server 3 refers to the account
database 6 to perform a real-time payment process by
electronic money as primary payment between accounts of the seller and the buyer. Secondary payment is performed between the financial institution server 13 and the secondary payment server 4 in a predetermined period of time thereafter.