To improve safety of electronic settlement without impairing convenience of a user in electronic commerce.

A electronic settlement service system is provided with a settlement service server 5 connected to a customer database 9 previously registering ID of a user, a personal identification number, a credit card number, and a shop database 10 registering the shop ID of an electronic firm, respectively. The settlement service server 5 connects user terminals 1, 2 and the electronic firm 6 through the Internet, receives a user's ID and personal identification number input from the user terminal and commodity delivery instruction data, gains access to the customer database 9, receives the credit card number after performing customer authentication, gains access to the shop database 10 to receive the shop ID, transmits the commodity price information with the credit card number and the shop ID to a payment authentication system 11 to receive the authentication result data to the credit card number, and transmits the authentication result data and commodity delivery instruction data to the electronic firm 6. The electronic firm 6 settles with the credit card company according to the authentication result data and sends the commodity to the user according to the delivery instruction data.