To provide a purchase mediation system which makes it possible to purchase an article by using not a card, but a network and pay for it.

When a member E having an ID number applies to a virtual shop C for a purchase of an article through the network (S7), A purchase mediator D which is informed (S8) by the virtual shop C informs the virtual shop C of vending acknowledgement (S11) after confirming the intention of the user E to purchase the article (S9 and S10), so that the virtual shop C provides the article to the member E (S12). A banking institution A receives data on payment in advance from the purchase mediator D and pays in the account of the virtual shop C in advance, and withdraws the purchase money from the account of the membership E to the account of the purchase mediator D according to withdrawal data from the purchase mediator.